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 = 1631 
WHERE 
  cscart_products_categories.product_id IN (
    13407, 13408, 13409, 13410, 13411, 13412, 
    13413, 13414, 13415, 13416, 13417, 
    13418, 13419, 13420, 13421, 13422, 
    13423, 13424, 13425, 13426, 13427, 
    13428, 13429, 13430
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00067

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost": 0.092277363,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_products_categories",
          "access_type": "range",
          "possible_keys": ["PRIMARY", "pt"],
          "key": "pt",
          "key_length": "3",
          "used_key_parts": ["product_id"],
          "loops": 1,
          "rows": 24,
          "cost": 0.02579124,
          "filtered": 100,
          "attached_condition": "cscart_products_categories.product_id in (13407,13408,13409,13410,13411,13412,13413,13414,13415,13416,13417,13418,13419,13420,13421,13422,13423,13424,13425,13426,13427,13428,13429,13430)",
          "using_index": true
        }
      },
      {
        "table": {
          "table_name": "cscart_categories",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY", "c_status", "p_category_id"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["category_id"],
          "ref": ["u508912950_dev_2025.cscart_products_categories.category_id"],
          "loops": 24,
          "rows": 1,
          "cost": 0.02474336,
          "filtered": 100,
          "attached_condition": "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')"
        }
      },
      {
        "table": {
          "table_name": "product_position_source",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY", "pt"],
          "key": "PRIMARY",
          "key_length": "6",
          "used_key_parts": ["category_id", "product_id"],
          "ref": [
            "const",
            "u508912950_dev_2025.cscart_products_categories.product_id"
          ],
          "loops": 24,
          "rows": 1,
          "cost": 0.02638176,
          "filtered": 100
        }
      }
    ]
  }
}

Result

product_id category_ids position
13407 1631M 0
13408 1631M 0
13409 1631M 0
13410 1631M 0
13411 1631M 0
13412 1631M 0
13413 1631M 0
13414 1631M 0
13415 1631M 0
13416 1631M 0
13417 1631M 0
13418 1631M 0
13419 1631M 0
13420 1631M 0
13421 1631M 0
13422 1631M 0
13423 1631M 0
13424 1631M 0
13425 1631M 0
13426 1631M 0
13427 1631M 0
13428 1631M 0
13429 1631M 0
13430 1631M 0