SELECT 
  pfv.feature_id, 
  pfv.product_id, 
  pfv.variant_id, 
  gp.group_id 
FROM 
  cscart_product_features_values AS pfv 
  INNER JOIN cscart_product_variation_group_products AS gp ON pfv.product_id = gp.product_id 
  INNER JOIN cscart_product_variation_group_features AS gpf ON gpf.group_id = gp.group_id 
  AND gpf.feature_id = pfv.feature_id 
WHERE 
  pfv.lang_code = 'en' 
  AND gp.group_id IN (
    2366, 2367, 2369, 2372, 2373, 2374, 2376, 
    2377, 2378, 2380, 2379, 2402, 2416, 
    2408, 2410, 2417, 2435, 2442, 2430, 
    2444, 2431, 1808, 2461, 1877
  )

Query time 0.00278

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "145.16"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "gp",
          "access_type": "range",
          "possible_keys": [
            "PRIMARY",
            "idx_group_id"
          ],
          "key": "idx_group_id",
          "used_key_parts": [
            "group_id"
          ],
          "key_length": "3",
          "rows_examined_per_scan": 121,
          "rows_produced_per_join": 121,
          "filtered": "100.00",
          "index_condition": "(`cscartdb`.`gp`.`group_id` in (2366,2367,2369,2372,2373,2374,2376,2377,2378,2380,2379,2402,2416,2408,2410,2417,2435,2442,2430,2444,2431,1808,2461,1877))",
          "cost_info": {
            "read_cost": "48.36",
            "eval_cost": "12.10",
            "prefix_cost": "60.46",
            "data_read_per_join": "1K"
          },
          "used_columns": [
            "product_id",
            "group_id"
          ]
        }
      },
      {
        "table": {
          "table_name": "gpf",
          "access_type": "ref",
          "possible_keys": [
            "PRIMARY",
            "idx_group_id"
          ],
          "key": "idx_group_id",
          "used_key_parts": [
            "group_id"
          ],
          "key_length": "3",
          "ref": [
            "cscartdb.gp.group_id"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 121,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "30.25",
            "eval_cost": "12.10",
            "prefix_cost": "102.81",
            "data_read_per_join": "12K"
          },
          "used_columns": [
            "feature_id",
            "group_id"
          ]
        }
      },
      {
        "table": {
          "table_name": "pfv",
          "access_type": "ref",
          "possible_keys": [
            "PRIMARY",
            "fl",
            "lang_code",
            "product_id",
            "fpl",
            "idx_product_feature_variant_id"
          ],
          "key": "fpl",
          "used_key_parts": [
            "feature_id",
            "product_id",
            "lang_code"
          ],
          "key_length": "12",
          "ref": [
            "cscartdb.gpf.feature_id",
            "cscartdb.gp.product_id",
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 121,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "30.25",
            "eval_cost": "12.10",
            "prefix_cost": "145.16",
            "data_read_per_join": "93K"
          },
          "used_columns": [
            "feature_id",
            "product_id",
            "variant_id",
            "lang_code"
          ]
        }
      }
    ]
  }
}