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 = 7204 
WHERE 
  cscart_products_categories.product_id IN (
    97437, 97438, 97439, 97440, 97441, 97442, 
    97443, 97444, 97445, 97446, 97447, 
    97448, 97449, 97450, 97451, 97452, 
    97453, 97454, 97455, 97456, 97457, 
    97458, 97459, 97460, 97461, 97462, 
    97463, 97464, 97465, 97466, 97467, 
    97468, 97469, 97470, 97471, 97472, 
    97473, 97474, 97475, 97476, 97477, 
    97478, 97479, 97480, 97481, 97482, 
    97483, 97484, 97485, 97486, 97487, 
    97488, 97489, 97490, 97491, 97492, 
    97493, 97494, 97495, 97496, 97497, 
    97498, 97499, 97500, 97501, 97502, 
    97503, 97504, 97505, 97525, 97526, 
    97527, 97528, 97529, 97530, 97531, 
    97532, 97533, 99068, 99069, 99070, 
    99071, 99072, 99073, 99074, 99075, 
    99076, 99077, 99078, 99079, 99080, 
    99081, 99082, 99083, 99084, 99085
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.01664

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "90.30"
    },
    "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": 100,
            "rows_produced_per_join": 100,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "10.30",
              "eval_cost": "10.00",
              "prefix_cost": "20.30",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (97437,97438,97439,97440,97441,97442,97443,97444,97445,97446,97447,97448,97449,97450,97451,97452,97453,97454,97455,97456,97457,97458,97459,97460,97461,97462,97463,97464,97465,97466,97467,97468,97469,97470,97471,97472,97473,97474,97475,97476,97477,97478,97479,97480,97481,97482,97483,97484,97485,97486,97487,97488,97489,97490,97491,97492,97493,97494,97495,97496,97497,97498,97499,97500,97501,97502,97503,97504,97505,97525,97526,97527,97528,97529,97530,97531,97532,97533,99068,99069,99070,99071,99072,99073,99074,99075,99076,99077,99078,99079,99080,99081,99082,99083,99084,99085))"
          }
        },
        {
          "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": 100,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "25.00",
              "eval_cost": "10.00",
              "prefix_cost": "55.30",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        },
        {
          "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": 5,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "25.00",
              "eval_cost": "0.50",
              "prefix_cost": "90.30",
              "data_read_per_join": "13K"
            },
            "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')))"
          }
        }
      ]
    }
  }
}