SELECT 
  feature_id, 
  variant_id, 
  value, 
  value_int 
FROM 
  cscart_product_features_values 
WHERE 
  product_id = 224455 
  AND lang_code = 'en'

Query time 0.00333

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "5187.60"
    },
    "table": {
      "table_name": "cscart_product_features_values",
      "access_type": "ref",
      "possible_keys": [
        "lang_code",
        "product_id",
        "idx_product_feature_variant_id"
      ],
      "key": "product_id",
      "used_key_parts": [
        "product_id"
      ],
      "key_length": "3",
      "ref": [
        "const"
      ],
      "rows_examined_per_scan": 4323,
      "rows_produced_per_join": 213,
      "filtered": "4.94",
      "index_condition": "(`webmarco`.`cscart_product_features_values`.`lang_code` = 'en')",
      "cost_info": {
        "read_cost": "4323.00",
        "eval_cost": "42.72",
        "prefix_cost": "5187.60",
        "data_read_per_join": "165K"
      },
      "used_columns": [
        "feature_id",
        "product_id",
        "variant_id",
        "value",
        "value_int",
        "lang_code"
      ]
    }
  }
}

Result

feature_id variant_id value value_int
611 8188
741 38288
834 59741
834 59742
834 59743
834 59744
834 59745
834 59746
834 59747
834 59748
834 59749
834 59750
834 59751
834 59752
834 59753
834 59754
834 59755
834 59756
834 59757
834 59758
834 59759
834 59760
834 59763
835 59704
837 59777
837 59778
837 59779
837 59780
838 59832
838 59833
840 59842
840 59843
840 59844
840 59845
840 59846
841 59847
841 59848
841 59849
841 59850
841 59851
841 59852
841 59853
841 59854
841 59855
841 59856
842 59857
842 59858
842 59859
842 59860
843 59861
843 59862
843 59863
843 59864
843 59865
844 59866
844 59867
844 59868
844 59869
845 59870
845 59871
845 59872
845 59873
845 59874
845 59875
845 59876
845 59877
845 59878
845 59879
845 59880
845 59881
846 59882
846 59883
846 59884
846 59885
846 59886
846 59887
847 59888
847 59889
848 59890
848 59891
848 59892
848 59893
848 59894
848 59895
848 59896
848 59897
849 59898
849 59899
849 59900
849 59901
849 59902
849 59903
849 59904
849 59905
850 59906
850 59907
850 59908
850 59909
850 59910
851 59911
851 59912
851 59913
851 59914
851 59915
851 59916
851 59917
851 59918
851 59919
852 59920
852 59921
853 59922
853 59923
853 59924
853 59925
853 59926
853 59927
853 59928
853 59929
853 59930
853 59931
853 61614
854 59932
854 59933
855 59934
856 59935
856 59936
856 59937
856 59938
856 59939
856 59940
856 59941