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 = 7257 
WHERE 
  cscart_products_categories.product_id IN (
    94520, 94521, 94522, 94523, 94524, 94525, 
    94526, 94527, 94528, 94529, 94530, 
    94531, 94532, 94533, 94534, 94535, 
    94536, 94537, 94538, 94539, 94540, 
    94541, 94542, 94543, 94544, 94545, 
    94546, 94547, 94548, 94549, 94550, 
    94551, 94552, 94553, 94554, 94555, 
    94556, 94557, 94558, 94559, 94560, 
    94561, 94562, 94563, 94564, 94565, 
    94566, 94567, 94568, 94569, 94570, 
    94571, 94572, 94573, 94574, 94575, 
    94576, 94577, 94578, 94579, 94580, 
    94581, 94582, 94583, 94584, 94585, 
    94586, 94587, 94588, 94827, 94828, 
    94829, 94830, 94831, 94839, 94840, 
    94841, 94843, 94850, 94851, 94852, 
    94853, 95309, 95315, 95316, 95318, 
    95319, 95365, 95366, 95367, 95368, 
    95369, 95370, 95371, 95372, 95373
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00250

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "134.28"
    },
    "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": 236,
            "rows_produced_per_join": 236,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "23.95",
              "eval_cost": "23.60",
              "prefix_cost": "47.55",
              "data_read_per_join": "3K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (94520,94521,94522,94523,94524,94525,94526,94527,94528,94529,94530,94531,94532,94533,94534,94535,94536,94537,94538,94539,94540,94541,94542,94543,94544,94545,94546,94547,94548,94549,94550,94551,94552,94553,94554,94555,94556,94557,94558,94559,94560,94561,94562,94563,94564,94565,94566,94567,94568,94569,94570,94571,94572,94573,94574,94575,94576,94577,94578,94579,94580,94581,94582,94583,94584,94585,94586,94587,94588,94827,94828,94829,94830,94831,94839,94840,94841,94843,94850,94851,94852,94853,95309,95315,95316,95318,95319,95365,95366,95367,95368,95369,95370,95371,95372,95373))"
          }
        },
        {
          "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": 11,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "59.00",
              "eval_cost": "1.18",
              "prefix_cost": "130.15",
              "data_read_per_join": "30K"
            },
            "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": 11,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "2.95",
              "eval_cost": "1.18",
              "prefix_cost": "134.28",
              "data_read_per_join": "188"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}