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 (
    98472, 98471, 98470, 98469, 98468, 98467, 
    98430, 98392, 98377, 97901, 97817, 
    97108, 92932, 92931, 98391, 98386, 
    92930, 98380, 98379, 98378
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00063

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
92930 6M 0
92931 6M 0
92932 6M 0
97108 6M 0
97817 6M 0
97901 6M 0
98377 6M 0
98378 6M 0
98379 6M 0
98380 6M 0
98386 6M 0
98391 6M 0
98392 6M 0
98430 6M 0
98467 6M 0
98468 6M 0
98469 6M 0
98470 6M 0
98471 6M 0
98472 6M 0