SELECT 
  product_id, 
  feature_id, 
  variant_id 
FROM 
  cscart_product_features_values 
WHERE 
  product_id IN (
    46795, 46794, 46793, 46792, 46791, 46790, 
    46789, 46788, 46787, 46786, 46785, 
    46784, 46783, 46782, 46781, 46737
  ) 
  AND feature_id IN (24710, 24709) 
  AND lang_code = 'vi'

Query time 0.00323

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": "PRIMARY",
          "key_length": "6",
          "used_key_parts": ["feature_id", "product_id"],
          "rows": 43,
          "filtered": 76.7441864,
          "attached_condition": "cscart_product_features_values.product_id in (46795,46794,46793,46792,46791,46790,46789,46788,46787,46786,46785,46784,46783,46782,46781,46737) and cscart_product_features_values.feature_id in (24710,24709) and cscart_product_features_values.lang_code = 'vi'",
          "using_index": true
        }
      }
    ]
  }
}