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 = 7231 
WHERE 
  cscart_products_categories.product_id IN (
    98671, 98672, 98673, 98674, 98675, 98676, 
    98677, 98678, 98679, 98680, 99683, 
    99684, 99685, 99686, 99687, 99688, 
    99689, 99690, 99691, 99692, 99693, 
    99694, 99695, 99696, 99832, 99833, 
    99834, 99843, 99845, 99846, 99848, 
    99850, 99852, 99853, 99855, 99857, 
    99860, 99862, 99865, 99867, 99869, 
    99872, 99874, 99875, 99877, 99879, 
    99880, 99882, 99884, 99895, 99896, 
    99899, 99900, 99903, 99904, 99907, 
    99908, 99911, 99912, 99915, 99916, 
    99933, 99935, 99936, 99937, 99939, 
    99941, 99943, 99944, 99945, 99946, 
    99947, 99949, 99951, 99952, 99953, 
    99954, 99955, 99957, 99959, 99960, 
    99961, 99963, 99965, 99967, 99968, 
    99969, 99970, 99971, 99972, 99973, 
    99975, 99977, 99978, 99979, 99981
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00228

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "54.77"
    },
    "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": 96,
            "rows_produced_per_join": 96,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "9.89",
              "eval_cost": "9.60",
              "prefix_cost": "19.49",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (98671,98672,98673,98674,98675,98676,98677,98678,98679,98680,99683,99684,99685,99686,99687,99688,99689,99690,99691,99692,99693,99694,99695,99696,99832,99833,99834,99843,99845,99846,99848,99850,99852,99853,99855,99857,99860,99862,99865,99867,99869,99872,99874,99875,99877,99879,99880,99882,99884,99895,99896,99899,99900,99903,99904,99907,99908,99911,99912,99915,99916,99933,99935,99936,99937,99939,99941,99943,99944,99945,99946,99947,99949,99951,99952,99953,99954,99955,99957,99959,99960,99961,99963,99965,99967,99968,99969,99970,99971,99972,99973,99975,99977,99978,99979,99981))"
          }
        },
        {
          "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": "24.00",
              "eval_cost": "0.48",
              "prefix_cost": "53.09",
              "data_read_per_join": "12K"
            },
            "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": "1.20",
              "eval_cost": "0.48",
              "prefix_cost": "54.77",
              "data_read_per_join": "76"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}