SELECT 
  product_id, 
  feature_id, 
  variant_id 
FROM 
  cscart_product_features_values 
WHERE 
  product_id IN (
    6828, 7008, 7009, 7032, 7033, 7071, 7034, 
    7110, 7096, 7095, 7072, 7111, 7112, 
    7113, 7180, 7181, 7182, 7223, 3190, 
    6757, 6745, 3197, 6769, 6751, 6835, 
    3288, 6831, 3294, 3168, 6740, 3169, 
    6741, 3273, 3284, 6821, 3280, 3180, 
    6752, 3181, 3272, 6820, 3278, 6826, 
    3279, 6827, 6837, 6838, 3275, 6839, 
    6823, 6842, 3295, 3281, 6762, 3187, 
    3176, 6766, 3195, 6739, 6737, 3167, 
    3166, 6738, 3193, 6755, 3198, 6763, 
    3282, 6746, 3185, 6836, 3289, 6830, 
    3283, 3271, 6832, 6843, 3177, 6756, 
    3192, 3183, 3174, 3191, 6748, 3171, 
    6754, 6758, 3194, 3182, 6759, 6743, 
    6747, 3172, 6753, 3184, 6742, 3865, 
    3186, 6765, 3175, 6829, 3291
  ) 
  AND feature_id IN (
    595, 628, 624, 625, 553, 626, 622, 623, 
    627, 636, 637, 641
  ) 
  AND lang_code = 'en'

Query time 0.01794

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "35.50"
    },
    "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",
      "used_key_parts": [
        "feature_id",
        "product_id",
        "variant_id",
        "lang_code"
      ],
      "key_length": "15",
      "rows_examined_per_scan": 122,
      "rows_produced_per_join": 122,
      "filtered": "100.00",
      "using_index_for_skip_scan": true,
      "cost_info": {
        "read_cost": "23.31",
        "eval_cost": "12.20",
        "prefix_cost": "35.51",
        "data_read_per_join": "94K"
      },
      "used_columns": [
        "feature_id",
        "product_id",
        "variant_id",
        "lang_code"
      ],
      "attached_condition": "((`test2_gaseus`.`cscart_product_features_values`.`product_id` in (6828,7008,7009,7032,7033,7071,7034,7110,7096,7095,7072,7111,7112,7113,7180,7181,7182,7223,3190,6757,6745,3197,6769,6751,6835,3288,6831,3294,3168,6740,3169,6741,3273,3284,6821,3280,3180,6752,3181,3272,6820,3278,6826,3279,6827,6837,6838,3275,6839,6823,6842,3295,3281,6762,3187,3176,6766,3195,6739,6737,3167,3166,6738,3193,6755,3198,6763,3282,6746,3185,6836,3289,6830,3283,3271,6832,6843,3177,6756,3192,3183,3174,3191,6748,3171,6754,6758,3194,3182,6759,6743,6747,3172,6753,3184,6742,3865,3186,6765,3175,6829,3291)) and (`test2_gaseus`.`cscart_product_features_values`.`feature_id` in (595,628,624,625,553,626,622,623,627,636,637,641)) and (`test2_gaseus`.`cscart_product_features_values`.`lang_code` = 'en'))"
    }
  }
}