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 = 4 
WHERE 
  cscart_products_categories.product_id IN (
    92499, 92498, 92486, 91950, 91930, 91909, 
    1417, 92477, 91779, 91778, 91777, 91776, 
    91775, 91774, 91773, 91772, 91771, 
    91770, 91769, 91768
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00087

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cscart_products_categories range PRIMARY,pt pt 3 24 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
1417 4M 0
91768 4M 0
91769 4M 0
91770 4M 0
91771 4M 0
91772 4M 0
91773 4M 0
91774 4M 0
91775 4M 0
91776 4M 0
91777 4M 0
91778 4M 0
91779 4M 0
91909 29,4M 0
91930 29,4M 0
91950 4M 0
92477 29,4M 0
92486 29,4M 0
92498 4M 0
92499 4M 0