SELECT 
  product_id, 
  feature_id, 
  variant_id 
FROM 
  cscart_product_features_values 
WHERE 
  product_id IN (
    36467, 36597, 36598, 36599, 36600, 36601, 
    36602, 36603, 36604, 36605, 36606, 
    36607, 36608, 36609, 36610, 36611, 
    36612, 36613
  ) 
  AND feature_id IN (23710) 
  AND lang_code = 'vi'

Query time 0.00580

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_product_features_values",
          "access_type": "range",
          "possible_keys": [
            "PRIMARY",
            "fl",
            "lang_code",
            "product_id",
            "fpl",
            "idx_product_feature_variant_id"
          ],
          "key": "idx_product_feature_variant_id",
          "key_length": "12",
          "used_key_parts": ["product_id", "feature_id", "lang_code"],
          "rows": 18,
          "filtered": 100,
          "attached_condition": "cscart_product_features_values.feature_id = 23710 and cscart_product_features_values.product_id in (36467,36597,36598,36599,36600,36601,36602,36603,36604,36605,36606,36607,36608,36609,36610,36611,36612,36613) and cscart_product_features_values.lang_code = 'vi'",
          "using_index": true
        }
      }
    ]
  }
}