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 = 22 
WHERE 
  cscart_products_categories.product_id IN (
    104503, 104502, 104566, 104565, 104564, 
    104563, 105544, 104462, 105512, 105462, 
    105461, 105460, 104547, 105405, 105404, 
    105403, 105402, 105401, 105400, 105399
  ) 
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 23 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
104462 22M 0
104502 22M 0
104503 22M 0
104547 22M 0
104563 22M 0
104564 22M 0
104565 22M 0
104566 22M 0
105399 22M 0
105400 22M 0
105401 22M 0
105402 22M 0
105403 22M 0
105404 22M 0
105405 22M 0
105460 33,22M 0
105461 33,22M 0
105462 33,22M 0
105512 22M 0
105544 22M 0