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 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 (
    (
      1 
      AND products.product_id IN (
        65994, 65995, 65996, 65997, 65998, 65999, 
        66000, 66001, 66002, 66003, 66004, 
        66005, 66006, 66007, 66008, 66009, 
        66010, 66011, 66012, 66013, 66014, 
        66015, 66016, 66017, 66018
      )
    ) 
    AND companies.status IN ('A') 
    AND prices.usergroup_id IN (0, 0, 1)
  ) 
  AND (
    products.available_worldwide = 'Y' 
    OR prc.country_code IS NULL
  ) 
GROUP BY 
  products.product_id 
ORDER BY 
  products.timestamp desc, 
  products.product_id desc, 
  products.product_id ASC

Query time 0.00128

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 products range PRIMARY,status PRIMARY 3 25 Using where; Using join buffer (flat, BNL join)
1 SIMPLE shared_descr eq_ref PRIMARY,product_id,company_id PRIMARY 13 toolboxdigitalshop_dev.products.product_id,const,const 1 Using where
1 SIMPLE prc eq_ref PRIMARY PRIMARY 9 toolboxdigitalshop_dev.products.product_id,const 1 Using where; Using index
1 SIMPLE prices ref usergroup,product_id,lower_limit,usergroup_id usergroup 3 toolboxdigitalshop_dev.products.product_id 1 Using where; Using index
1 SIMPLE descr1 eq_ref PRIMARY,product_id PRIMARY 9 toolboxdigitalshop_dev.products.product_id,const 1 Using where
1 SIMPLE products_categories ref PRIMARY,pt pt 3 toolboxdigitalshop_dev.products.product_id 1 Using index
1 SIMPLE cscart_categories eq_ref PRIMARY,c_status,p_category_id PRIMARY 3 toolboxdigitalshop_dev.products_categories.category_id 1 Using where

Result

product_id product company_name product_type parent_product_id
66018 Uncivilized Hour (Original Mix) Toolbox Digital Shop P 0
66017 Bello (Patrick DSP Remix) Toolbox Digital Shop P 0
66016 Manifest (Original Mix) Toolbox Digital Shop P 0
66015 Midipro (Tito K. Remix) Toolbox Digital Shop P 0
66014 Ritam (Original Mix) Toolbox Digital Shop P 0
66013 Strong Rhythm (Original Mix) Toolbox Digital Shop P 0
66012 Silence Fiction (Original Mix) Toolbox Digital Shop P 0
66011 Mafesh (Original Mix) Toolbox Digital Shop P 0
66010 Lime Lite (Tito K. Remix) Toolbox Digital Shop P 0
66009 Hotte Hoschi 246 (Original Mix) Toolbox Digital Shop P 0
66008 Micropoint (Original Mix) Toolbox Digital Shop P 0
66007 Psyche (Tito K. Remix) Toolbox Digital Shop P 0
66006 The Splinter (Original Mix) Toolbox Digital Shop P 0
66005 Killer (Original Mix) Toolbox Digital Shop P 0
66004 Calfskin Smack (Original Mix) Toolbox Digital Shop P 0
66003 Outside World (Original Mix) Toolbox Digital Shop P 0
66002 A Little Abuse (Mark Cowax Remix) Toolbox Digital Shop P 0
66001 Jet Pack (Original Mix) Toolbox Digital Shop P 0
66000 Silent Two (Original Mix) Toolbox Digital Shop P 0
65999 Drakc (Original Mix) Toolbox Digital Shop P 0
65998 3PhaZe (GSM Remix) Toolbox Digital Shop P 0
65997 The Bassdrum (Original Mix) Toolbox Digital Shop P 0
65996 Bad Religion (Asparuh & Jared Pastore Remix) Toolbox Digital Shop P 0
65995 Einstein (Kevin Kranz Remix) Toolbox Digital Shop P 0
65994 In The World Mortal Darkness (Original Mix) Toolbox Digital Shop P 0