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 = 40 
WHERE 
  cscart_products_categories.product_id IN (
    137, 88, 126, 31, 51358, 115, 80, 37, 11, 
    140, 41, 30, 90, 38, 124, 81, 56, 82, 116, 
    117, 125, 106, 39, 193, 40, 22710, 22711, 
    17, 57, 122, 58, 5
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00172

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "96.30"
    },
    "grouping_operation": {
      "using_filesort": false,
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_products_categories",
            "access_type": "range",
            "possible_keys": [
              "PRIMARY",
              "pt"
            ],
            "key": "pt",
            "used_key_parts": [
              "product_id"
            ],
            "key_length": "3",
            "rows_examined_per_scan": 108,
            "rows_produced_per_join": 108,
            "filtered": "100.00",
            "index_condition": "(`test_uchur_k`.`cscart_products_categories`.`product_id` in (137,88,126,31,51358,115,80,37,11,140,41,30,90,38,124,81,56,82,116,117,125,106,39,193,40,22710,22711,17,57,122,58,5))",
            "cost_info": {
              "read_cost": "45.81",
              "eval_cost": "10.80",
              "prefix_cost": "56.61",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ]
          }
        },
        {
          "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": [
              "test_uchur_k.cscart_products_categories.category_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 5,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "27.00",
              "eval_cost": "0.54",
              "prefix_cost": "94.41",
              "data_read_per_join": "28K"
            },
            "used_columns": [
              "category_id",
              "storefront_id",
              "usergroup_ids",
              "status"
            ],
            "attached_condition": "((`test_uchur_k`.`cscart_categories`.`storefront_id` in (0,1)) and ((`test_uchur_k`.`cscart_categories`.`usergroup_ids` = '') or (0 <> find_in_set(0,`test_uchur_k`.`cscart_categories`.`usergroup_ids`)) or (0 <> find_in_set(1,`test_uchur_k`.`cscart_categories`.`usergroup_ids`))) and (`test_uchur_k`.`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",
              "test_uchur_k.cscart_products_categories.product_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 5,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "1.35",
              "eval_cost": "0.54",
              "prefix_cost": "96.30",
              "data_read_per_join": "86"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}

Result

product_id category_ids position
5 6,42,40M 0
11 42,8,394,40M 0
17 6,44,40M 0
30 44,18,391,40M 0
31 43,391,18,40M 0
37 42,10,40M 0
38 10,42,40M 0
39 10,42,40M 0
40 10,44,40M 0
41 10,43,40M 0
56 42,8,394,40M 0
57 6,44,40M 0
58 6,43,40M 0
80 26,40M 0
81 43,8,394,40M 0
82 44,8,394,40M 0
88 235,42,40M 0
90 43,9,40M 0
106 43,6,394,40M 0
115 42,8,394,40M 0
116 42,8,394,40M 0
117 42,8,394,40M 0
122 42,6,40M 0
124 42,7,40M 0
125 42,7,40M 0
126 42,8,394,40M 0
137 42,7,40M 0
140 25,42,40M 0
193 43,9,40M 0
22710 392,42,40,18M 0
22711 392,42,40,18M 0
51358 391,42,18,40M 0