SELECT 
  cscart_products_categories.product_id, 
  GROUP_CONCAT(
    IF(
      cscart_products_categories.link_type = "M", 
      CONCAT(
        cscart_products_categories.category_id, 
        "M"
      ), 
      cscart_products_categories.category_id
    )
  ) AS category_ids, 
  product_position_source.position AS position 
FROM 
  cscart_products_categories 
  INNER JOIN cscart_categories ON cscart_categories.category_id = cscart_products_categories.category_id 
  AND cscart_categories.storefront_id IN (0, 1) 
  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') 
  LEFT JOIN cscart_products_categories AS product_position_source ON cscart_products_categories.product_id = product_position_source.product_id 
  AND product_position_source.category_id = 6 
WHERE 
  cscart_products_categories.product_id IN (
    93222, 93224, 93165, 92338, 92337, 93157, 
    93156, 93104, 93103, 93058, 93036, 
    92955, 92835, 92833, 92522, 92521, 
    92504, 92502, 92344, 92281
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00058

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cscart_products_categories range PRIMARY,pt pt 3 20 Using where; Using index
1 SIMPLE cscart_categories eq_ref PRIMARY,c_status,p_category_id PRIMARY 3 toolboxdigitalshop_dev.cscart_products_categories.category_id 1 Using where
1 SIMPLE product_position_source eq_ref PRIMARY,pt PRIMARY 6 const,toolboxdigitalshop_dev.cscart_products_categories.product_id 1

Result

product_id category_ids position
92281 6M 0
92337 6M 0
92338 6M 0
92344 6M 0
92502 6M 0
92504 6M 0
92521 6M 0
92522 6M 0
92833 6M 0
92835 6M 0
92955 6M 0
93036 6M 0
93058 6M 0
93103 6M 0
93104 6M 0
93156 6M 0
93157 6M 0
93165 6M 0
93222 6M 0
93224 6M 0