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 (
    100653, 100652, 100651, 100650, 100649, 
    101334, 101333, 101332, 101331, 101330, 
    101329, 101328, 101327, 101326, 101325, 
    101324, 101323, 101322, 101321, 101320
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00066

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cscart_products_categories range PRIMARY,pt pt 3 25 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
100649 32,22M 0
100650 32,22M 0
100651 32,22M 0
100652 32,22M 0
100653 32,22M 0
101320 22M 0
101321 22M 0
101322 22M 0
101323 22M 0
101324 22M 0
101325 22M 0
101326 22M 0
101327 22M 0
101328 22M 0
101329 22M 0
101330 22M 0
101331 22M 0
101332 22M 0
101333 22M 0
101334 22M 0