SELECT 
  cscart_product_feature_variant_descriptions.variant, 
  cscart_product_feature_variants.variant_id, 
  cscart_product_feature_variants.feature_id, 
  cscart_product_features_values.variant_id as selected, 
  cscart_product_features.feature_type 
FROM 
  cscart_product_feature_variants 
  LEFT JOIN cscart_product_feature_variant_descriptions ON cscart_product_feature_variant_descriptions.variant_id = cscart_product_feature_variants.variant_id 
  AND cscart_product_feature_variant_descriptions.lang_code = 'en' 
  LEFT JOIN cscart_product_features_values ON cscart_product_features_values.variant_id = cscart_product_feature_variants.variant_id 
  AND cscart_product_features_values.lang_code = 'en' 
  AND cscart_product_features_values.product_id = 217 
  AND cscart_product_features_values.feature_id = cscart_product_feature_variants.feature_id 
  LEFT JOIN cscart_product_features ON cscart_product_features.feature_id = cscart_product_feature_variants.feature_id 
WHERE 
  1 
  AND cscart_product_feature_variants.feature_id IN (15, 17) 
GROUP BY 
  cscart_product_feature_variants.variant_id 
ORDER BY 
  cscart_product_feature_variants.position, 
  cscart_product_feature_variant_descriptions.variant

Query time 0.00090

JSON explain

{
  "query_block": {
    "select_id": 1,
    "filesort": {
      "sort_key": "cscart_product_feature_variants.position, cscart_product_feature_variant_descriptions.variant",
      "temporary_table": {
        "nested_loop": [
          {
            "table": {
              "table_name": "cscart_product_feature_variants",
              "access_type": "ALL",
              "possible_keys": ["feature_id"],
              "rows": 158,
              "filtered": 20.88607597,
              "attached_condition": "cscart_product_feature_variants.feature_id in (15,17)"
            }
          },
          {
            "table": {
              "table_name": "cscart_product_feature_variant_descriptions",
              "access_type": "eq_ref",
              "possible_keys": ["PRIMARY"],
              "key": "PRIMARY",
              "key_length": "9",
              "used_key_parts": ["variant_id", "lang_code"],
              "ref": [
                "n764025_kutubminar123.cscart_product_feature_variants.variant_id",
                "const"
              ],
              "rows": 1,
              "filtered": 100,
              "attached_condition": "trigcond(cscart_product_feature_variant_descriptions.lang_code = 'en')"
            }
          },
          {
            "table": {
              "table_name": "cscart_product_features_values",
              "access_type": "eq_ref",
              "possible_keys": [
                "PRIMARY",
                "fl",
                "variant_id",
                "lang_code",
                "product_id",
                "fpl",
                "idx_product_feature_variant_id"
              ],
              "key": "PRIMARY",
              "key_length": "15",
              "used_key_parts": [
                "feature_id",
                "product_id",
                "variant_id",
                "lang_code"
              ],
              "ref": [
                "n764025_kutubminar123.cscart_product_feature_variants.feature_id",
                "const",
                "n764025_kutubminar123.cscart_product_feature_variants.variant_id",
                "const"
              ],
              "rows": 1,
              "filtered": 100,
              "attached_condition": "trigcond(cscart_product_features_values.lang_code = 'en')",
              "using_index": true
            }
          },
          {
            "table": {
              "table_name": "cscart_product_features",
              "access_type": "eq_ref",
              "possible_keys": ["PRIMARY"],
              "key": "PRIMARY",
              "key_length": "3",
              "used_key_parts": ["feature_id"],
              "ref": [
                "n764025_kutubminar123.cscart_product_feature_variants.feature_id"
              ],
              "rows": 1,
              "filtered": 100
            }
          }
        ]
      }
    }
  }
}

Result

variant variant_id feature_id selected feature_type
16GB 45 17 S
1TB 47 17 S
256GB 64 17 S
256MB 79 17 S
2GB 81 17 S
320GB 50 17 S
32GB 54 17 S
4GB 75 17 S
500GB 48 17 48 S
512MB 82 17 S
640GB 60 17 S
750GB 62 17 S
8GB 72 17 S
Android 2.1 84 15 S
Android 2.2, Froyo 55 15 S
Android 2.3, Gingerbread 66 15 S
Android 3.1, Honeycomb 52 15 S
Android 3.2, Honeycomb 58 15 S
Android 4.0, Ice Cream Sandwich 73 15 S
Nokia OS 76 15 S
Symbian OS 78 15 S
Windows 7 Home Basic 49 15 S
Windows 7 Home Premium 46 15 46 S
Windows Phone 7.5, Mango 69 15 S
iOS 5 39 15 S