SELECT 
  SQL_CALC_FOUND_ROWS products.product_id, 
  IF(
    shared_descr.product_id IS NOT NULL, 
    shared_descr.product, descr1.product
  ) as product, 
  companies.company as company_name, 
  products.product_type, 
  products.parent_product_id 
FROM 
  cscart_products as products 
  LEFT JOIN cscart_product_descriptions as descr1 ON descr1.product_id = products.product_id 
  AND descr1.lang_code = 'en' 
  LEFT JOIN cscart_product_prices as prices ON prices.product_id = products.product_id 
  AND prices.lower_limit = 1 
  LEFT JOIN cscart_companies AS companies ON companies.company_id = products.company_id 
  INNER JOIN cscart_products_categories as products_categories ON products_categories.product_id = products.product_id 
  INNER JOIN cscart_categories ON cscart_categories.category_id = products_categories.category_id 
  AND (
    cscart_categories.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_categories.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_categories.usergroup_ids
    )
  ) 
  AND cscart_categories.status IN ('A', 'H') 
  AND cscart_categories.storefront_id IN (0, 1) 
  LEFT JOIN cscart_ult_product_descriptions shared_descr ON shared_descr.product_id = products.product_id 
  AND shared_descr.company_id = 1 
  AND shared_descr.lang_code = 'en' 
  LEFT JOIN cscart_product_restricted_countries AS prc ON prc.product_id = products.product_id 
  AND prc.country_code = 'US' 
WHERE 
  1 
  AND cscart_categories.category_id IN (4, 29, 30, 36) 
  AND companies.status IN ('A') 
  AND (
    products.usergroup_ids = '' 
    OR FIND_IN_SET(0, products.usergroup_ids) 
    OR FIND_IN_SET(1, products.usergroup_ids)
  ) 
  AND products.status IN ('A') 
  AND prices.usergroup_id IN (0, 0, 1) 
  AND (
    products.available_worldwide = 'Y' 
    OR prc.country_code IS NULL
  ) 
  AND !(
    products.out_of_stock_actions = 'B' && products.avail_since > 1747960163
  ) 
  AND products.parent_product_id = 0 
GROUP BY 
  products.product_id 
ORDER BY 
  products.timestamp desc, 
  products.product_id desc, 
  products.product_id ASC 
LIMIT 
  7360, 40

Query time 0.34327

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE companies ALL PRIMARY 1 Using where; Using temporary; Using filesort
1 SIMPLE cscart_categories range PRIMARY,c_status,p_category_id PRIMARY 3 4 Using where; Using join buffer (flat, BNL join)
1 SIMPLE products_categories ref PRIMARY,pt PRIMARY 3 toolboxdigitalshop_dev.cscart_categories.category_id 908 Using index
1 SIMPLE products eq_ref PRIMARY,status,idx_parent_product_id PRIMARY 3 toolboxdigitalshop_dev.products_categories.product_id 1 Using where
1 SIMPLE shared_descr eq_ref PRIMARY,product_id,company_id PRIMARY 13 toolboxdigitalshop_dev.products_categories.product_id,const,const 1 Using where
1 SIMPLE prc eq_ref PRIMARY PRIMARY 9 toolboxdigitalshop_dev.products_categories.product_id,const 1 Using where; Using index
1 SIMPLE descr1 eq_ref PRIMARY,product_id PRIMARY 9 toolboxdigitalshop_dev.products_categories.product_id,const 1 Using where
1 SIMPLE prices ref usergroup,product_id,lower_limit,usergroup_id usergroup 3 toolboxdigitalshop_dev.products_categories.product_id 1 Using where; Using index

Result

product_id product company_name product_type parent_product_id
69132 Way You Move (Pick & Load's Mindblowing Remix) Toolbox Digital Shop P 0
69131 The Grapevine (Original Mix) Toolbox Digital Shop P 0
69252 Walking On Sunshine (Original Mix) Toolbox Digital Shop P 0
69412 Closer (Original Mix) Toolbox Digital Shop P 0
69405 Resurgence (Bowie666 Remix) Toolbox Digital Shop P 0
69404 Resurgence (AMT Remix) Toolbox Digital Shop P 0
68938 Intervention (Original Mix) Toolbox Digital Shop P 0
68937 TRK 4 (Original Mix) Toolbox Digital Shop P 0
68936 Let You Go (The Snail Remix) Toolbox Digital Shop P 0
68934 Rock Da House (Original Mix) Toolbox Digital Shop P 0
68933 Do The Nasty (2001 Original Mix) Toolbox Digital Shop P 0
68932 No Respect (Original Mix) Toolbox Digital Shop P 0
68931 Music-On (Original Mix) Toolbox Digital Shop P 0
68930 Arriba Arribaaa!!! (Original Mix) Toolbox Digital Shop P 0
68929 Gimme My Shit Back (Original Mix) Toolbox Digital Shop P 0
68928 Birthright (Original Mix) Toolbox Digital Shop P 0
68927 99 Beans & A Gurn Ain't One (Original Mix) Toolbox Digital Shop P 0
68926 Sweet Thighs (Original Mix) Toolbox Digital Shop P 0
68925 Gay Fish (Nikkdbubble & Filthy Kitten Remix) Toolbox Digital Shop P 0
68924 The Hybrid (Original Mix) Toolbox Digital Shop P 0
68923 Future (Original Mix) Toolbox Digital Shop P 0
68922 Banshee (Original Mix) Toolbox Digital Shop P 0
68918 Whiplash (Original Mix) Toolbox Digital Shop P 0
68917 What We Wanna Do (Joz B Remix) Toolbox Digital Shop P 0
68915 Dirty Love (Vandalize Remix) Toolbox Digital Shop P 0
68913 Fallin Apart (Original Mix) Toolbox Digital Shop P 0
68857 Fly Away (Original Mix) Toolbox Digital Shop P 0
68856 Hide Da Reefa (Original Mix) Toolbox Digital Shop P 0
68855 Absolutely Fabulous (Original Mix) Toolbox Digital Shop P 0
68854 Gold (Original Mix) Toolbox Digital Shop P 0
68853 Take Me Higher (Elivate & The Cheeky Boys Remix) Toolbox Digital Shop P 0
68852 Higher (Original Mix) Toolbox Digital Shop P 0
68851 Dreamer (Original Mix) Toolbox Digital Shop P 0
68849 HardFace (Original Mix) Toolbox Digital Shop P 0
68846 Evolved (Original Mix) Toolbox Digital Shop P 0
68842 Mushroom Jelly! (Poomstyles Remix) Toolbox Digital Shop P 0
68841 Getting Warmer (Original Mix) Toolbox Digital Shop P 0
68840 Hits With No Errors (Pokyeo FX Remix) Toolbox Digital Shop P 0
68839 The Grapevine (Original Mix) Toolbox Digital Shop P 0
69286 Nikita (Original Mix) Toolbox Digital Shop P 0