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 = 7229 
WHERE 
  cscart_products_categories.product_id IN (
    99013, 99014, 99015, 99016, 99017, 99018, 
    99019, 99588, 99589, 99590, 99591, 
    99592, 99593, 99594, 99595, 99596, 
    99597, 99598, 99599, 99600, 99601, 
    99602, 99603, 99604, 99605, 99606, 
    99607, 99608, 99609, 99610
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00132

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "17.29"
    },
    "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": 30,
            "rows_produced_per_join": 30,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "3.27",
              "eval_cost": "3.00",
              "prefix_cost": "6.27",
              "data_read_per_join": "480"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (99013,99014,99015,99016,99017,99018,99019,99588,99589,99590,99591,99592,99593,99594,99595,99596,99597,99598,99599,99600,99601,99602,99603,99604,99605,99606,99607,99608,99609,99610))"
          }
        },
        {
          "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": 1,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "7.50",
              "eval_cost": "0.15",
              "prefix_cost": "16.77",
              "data_read_per_join": "3K"
            },
            "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": 1,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "0.38",
              "eval_cost": "0.15",
              "prefix_cost": "17.30",
              "data_read_per_join": "24"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}

Result

product_id category_ids position
99013 7229M 0
99014 7229M 0
99015 7229M 0
99016 7229M 0
99017 7229M 0
99018 7229M 0
99019 7229M 0
99588 7229M 0
99589 7229M 0
99590 7229M 0
99591 7229M 0
99592 7229M 0
99593 7229M 0
99594 7229M 0
99595 7229M 0
99596 7229M 0
99597 7229M 0
99598 7229M 0
99599 7229M 0
99600 7229M 0
99601 7229M 0
99602 7229M 0
99603 7229M 0
99604 7229M 0
99605 7229M 0
99606 7229M 0
99607 7229M 0
99608 7229M 0
99609 7229M 0
99610 7229M 0