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 = 7214 
WHERE 
  cscart_products_categories.product_id IN (
    88583, 88674, 88721, 88582, 90833, 88545, 
    88403, 88765, 88566, 87617, 87625, 
    88673, 88720, 88401, 88565, 88564, 
    87636, 89107, 89114, 90832, 87621, 
    87623, 88671, 88718, 87635, 87638, 
    87640, 87632, 88561, 87637
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00162

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "51.37"
    },
    "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": 90,
            "rows_produced_per_join": 90,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "9.29",
              "eval_cost": "9.00",
              "prefix_cost": "18.29",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (88583,88674,88721,88582,90833,88545,88403,88765,88566,87617,87625,88673,88720,88401,88565,88564,87636,89107,89114,90832,87621,87623,88671,88718,87635,87638,87640,87632,88561,87637))"
          }
        },
        {
          "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": 4,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "22.50",
              "eval_cost": "0.45",
              "prefix_cost": "49.79",
              "data_read_per_join": "11K"
            },
            "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": 4,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "1.13",
              "eval_cost": "0.45",
              "prefix_cost": "51.37",
              "data_read_per_join": "72"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}

Result

product_id category_ids position
87617 7210,7211,7214M 0
87621 7210,7211,7214M 0
87623 7210,7211,7214M 0
87625 7210,7211,7214M 0
87632 7210,7211,7214M 0
87635 7210,7211,7214M 0
87636 7210,7211,7214M 0
87637 7210,7211,7214M 0
87638 7210,7211,7214M 0
87640 7210,7211,7214M 0
88401 7210,7211,7214M 0
88403 7210,7211,7214M 0
88545 7210,7211,7214M 0
88561 7210,7211,7214M 0
88564 7210,7211,7214M 0
88565 7210,7211,7214M 0
88566 7210,7211,7214M 0
88582 7210,7211,7214M 0
88583 7210,7211,7214M 0
88671 7210,7211,7214M 0
88673 7210,7211,7214M 0
88674 7210,7211,7214M 0
88718 7210,7211,7214M 0
88720 7210,7211,7214M 0
88721 7210,7211,7214M 0
88765 7210,7211,7214M 0
89107 7210,7211,7214M 0
89114 7210,7211,7214M 0
90832 7210,7211,7214M 0
90833 7210,7211,7214M 0