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 = 7270 
WHERE 
  cscart_products_categories.product_id IN (
    88353, 88354, 88271, 89674, 88351, 88352, 
    89670, 88106, 88118, 88130, 88264, 
    88273, 88274, 88270, 88268, 88269, 
    89669, 89662, 89672, 89673, 88267, 
    89667, 89668, 88348
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00136

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "41.14"
    },
    "grouping_operation": {
      "using_filesort": false,
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_products_categories",
            "access_type": "range",
            "possible_keys": [
              "PRIMARY",
              "link_type",
              "pt"
            ],
            "key": "pt",
            "used_key_parts": [
              "product_id"
            ],
            "key_length": "3",
            "rows_examined_per_scan": 72,
            "rows_produced_per_join": 72,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "7.49",
              "eval_cost": "7.20",
              "prefix_cost": "14.69",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (88353,88354,88271,89674,88351,88352,89670,88106,88118,88130,88264,88273,88274,88270,88268,88269,89669,89662,89672,89673,88267,89667,89668,88348))"
          }
        },
        {
          "table": {
            "table_name": "cscart_categories",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "c_status",
              "p_category_id"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id"
            ],
            "key_length": "3",
            "ref": [
              "nuie_scalesta_net.cscart_products_categories.category_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 3,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "18.00",
              "eval_cost": "0.36",
              "prefix_cost": "39.89",
              "data_read_per_join": "9K"
            },
            "used_columns": [
              "category_id",
              "usergroup_ids",
              "status",
              "storefront_id"
            ],
            "attached_condition": "((`nuie_scalesta_net`.`cscart_categories`.`storefront_id` in (0,1)) and ((`nuie_scalesta_net`.`cscart_categories`.`usergroup_ids` = '') or (0 <> find_in_set(0,`nuie_scalesta_net`.`cscart_categories`.`usergroup_ids`)) or (0 <> find_in_set(1,`nuie_scalesta_net`.`cscart_categories`.`usergroup_ids`))) and (`nuie_scalesta_net`.`cscart_categories`.`status` in ('A','H')))"
          }
        },
        {
          "table": {
            "table_name": "product_position_source",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "pt"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id",
              "product_id"
            ],
            "key_length": "6",
            "ref": [
              "const",
              "nuie_scalesta_net.cscart_products_categories.product_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 3,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "0.90",
              "eval_cost": "0.36",
              "prefix_cost": "41.15",
              "data_read_per_join": "57"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}

Result

product_id category_ids position
88106 7237,7270,7277M 0
88118 7237,7270,7293M 0
88130 7237,7270,7299M 0
88264 7237,7270,7271M 0
88267 7237,7270,7271M 0
88268 7237,7270,7271M 0
88269 7237,7270,7271M 0
88270 7237,7270,7271M 0
88271 7237,7270,7271M 0
88273 7237,7270,7271M 0
88274 7237,7270,7271M 0
88348 7237,7270,7277M 0
88351 7237,7270,7277M 0
88352 7237,7270,7277M 0
88353 7237,7270,7277M 0
88354 7237,7270,7277M 0
89662 7237,7270,7293M 0
89667 7237,7270,7293M 0
89668 7237,7270,7293M 0
89669 7237,7270,7293M 0
89670 7237,7270,7293M 0
89672 7237,7270,7293M 0
89673 7237,7270,7293M 0
89674 7237,7270,7293M 0