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 = 7211 
WHERE 
  cscart_products_categories.product_id IN (
    99057, 99058, 99059, 99060, 99061, 99062, 
    99063, 99064, 99065, 99067, 99111, 
    99112, 99115, 99116, 99118, 99119, 
    99122, 99124, 99126, 99129, 99130, 
    99132, 99134, 99143, 99163, 99164, 
    99166, 99172, 99173, 99175
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00266

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "49.66"
    },
    "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": 87,
            "rows_produced_per_join": 87,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "8.99",
              "eval_cost": "8.70",
              "prefix_cost": "17.69",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (99057,99058,99059,99060,99061,99062,99063,99064,99065,99067,99111,99112,99115,99116,99118,99119,99122,99124,99126,99129,99130,99132,99134,99143,99163,99164,99166,99172,99173,99175))"
          }
        },
        {
          "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": "21.75",
              "eval_cost": "0.44",
              "prefix_cost": "48.14",
              "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": "1.09",
              "eval_cost": "0.44",
              "prefix_cost": "49.66",
              "data_read_per_join": "69"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}

Result

product_id category_ids position
99057 7241,7309,7346,7208M
99058 7241,7309,7346,7208M
99059 7241,7309,7346,7208M
99060 7241,7309,7346,7208M
99061 7241,7309,7346,7208M
99062 7241,7309,7346,7208M
99063 7241,7309,7346,7208M
99064 7241,7309,7346,7208M
99065 7241,7309,7346,7208M
99067 7241,7309,7346,7208M
99111 7345,7347,7259M
99112 7320,7260M
99115 7320,7260M
99116 7320,7260M
99118 7320,7260M
99119 7320,7260M
99122 7345,7347,7259M
99124 7345,7347,7259M
99126 7345,7347,7259M
99129 7345,7347,7259M
99130 7320,7260M
99132 7320,7260M
99134 7320,7260M
99143 7320,7260M
99163 7345,7347,7259M
99164 7320,7260M
99166 7320,7260M
99172 7345,7347,7259M
99173 7320,7260M
99175 7320,7260M