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 = 7237 
WHERE 
  cscart_products_categories.product_id IN (
    100579, 100580, 100581, 100582, 100583, 
    100584, 100585, 100586, 100587, 100588, 
    100589, 100590, 100591, 100592, 100593, 
    101047, 101048, 101049, 101050, 101051, 
    101052, 101053, 101574, 101575, 101576, 
    101577, 101578, 101579, 101580, 101581, 
    101582, 101583, 101584, 101585, 101586, 
    101587, 101588, 101589, 101590, 101591, 
    101592, 101593, 101594, 101595, 101596, 
    101597, 101598, 101599, 101600, 101601, 
    101602, 101603, 101604, 101605, 101606, 
    101607, 101608, 101609, 101610, 101611, 
    101612, 101613, 101614, 101615, 101616, 
    101617, 101618, 101619, 101620, 101621, 
    101622, 101623, 101624
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.01521

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "65.99"
    },
    "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": 73,
            "rows_produced_per_join": 73,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "7.59",
              "eval_cost": "7.30",
              "prefix_cost": "14.89",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (100579,100580,100581,100582,100583,100584,100585,100586,100587,100588,100589,100590,100591,100592,100593,101047,101048,101049,101050,101051,101052,101053,101574,101575,101576,101577,101578,101579,101580,101581,101582,101583,101584,101585,101586,101587,101588,101589,101590,101591,101592,101593,101594,101595,101596,101597,101598,101599,101600,101601,101602,101603,101604,101605,101606,101607,101608,101609,101610,101611,101612,101613,101614,101615,101616,101617,101618,101619,101620,101621,101622,101623,101624))"
          }
        },
        {
          "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": 73,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "18.25",
              "eval_cost": "7.30",
              "prefix_cost": "40.44",
              "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": 3,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "18.25",
              "eval_cost": "0.37",
              "prefix_cost": "65.99",
              "data_read_per_join": "9K"
            },
            "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')))"
          }
        }
      ]
    }
  }
}