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 = 7184 
WHERE 
  cscart_products_categories.product_id IN (
    99659, 99660, 99661, 99662, 99663, 99664, 
    99665, 99666, 99667, 99668, 100144, 
    100145, 100146, 100147, 100148, 100149, 
    100292, 100293, 100294, 100295, 100480, 
    100481, 100482, 100483, 100484, 100485, 
    100486, 100487, 100488, 100489, 100490, 
    100491, 100492, 100493, 100494, 100495, 
    100496, 100497, 100498, 100499, 100504, 
    100505, 100506, 100507, 100508, 100509, 
    100510, 100511, 100512, 100513, 100514, 
    100515, 100516, 100517, 100518, 100519, 
    100520, 100521, 100522, 100523, 100524, 
    100525, 100526, 100527, 100528, 100529, 
    100530, 100531, 100532, 100533, 100534, 
    100535, 100536, 100537, 100538, 100539, 
    100594, 100595, 100596, 100597, 100612, 
    100613, 100614, 100615, 100616, 100617, 
    100618, 100619, 100620, 100621, 100622, 
    100623, 100624, 100625, 100626, 100627
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00256

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "87.14"
    },
    "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": 153,
            "rows_produced_per_join": 153,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "15.62",
              "eval_cost": "15.30",
              "prefix_cost": "30.92",
              "data_read_per_join": "2K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (99659,99660,99661,99662,99663,99664,99665,99666,99667,99668,100144,100145,100146,100147,100148,100149,100292,100293,100294,100295,100480,100481,100482,100483,100484,100485,100486,100487,100488,100489,100490,100491,100492,100493,100494,100495,100496,100497,100498,100499,100504,100505,100506,100507,100508,100509,100510,100511,100512,100513,100514,100515,100516,100517,100518,100519,100520,100521,100522,100523,100524,100525,100526,100527,100528,100529,100530,100531,100532,100533,100534,100535,100536,100537,100538,100539,100594,100595,100596,100597,100612,100613,100614,100615,100616,100617,100618,100619,100620,100621,100622,100623,100624,100625,100626,100627))"
          }
        },
        {
          "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": 7,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "38.25",
              "eval_cost": "0.77",
              "prefix_cost": "84.47",
              "data_read_per_join": "19K"
            },
            "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": 7,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "1.91",
              "eval_cost": "0.77",
              "prefix_cost": "87.14",
              "data_read_per_join": "122"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}