SELECT 
  cscart_product_feature_variants.variant_id, 
  cscart_product_feature_variant_descriptions.variant 
FROM 
  cscart_product_features 
  INNER JOIN cscart_product_feature_variants ON cscart_product_feature_variants.feature_id = cscart_product_features.feature_id 
  LEFT JOIN cscart_product_feature_variant_descriptions ON cscart_product_feature_variants.variant_id = cscart_product_feature_variant_descriptions.variant_id 
  AND lang_code = 'en' 
WHERE 
  cscart_product_features.feature_type = 'E' 
  AND cscart_product_features.status = "A" 
ORDER BY 
  TRIM(
    cscart_product_feature_variant_descriptions.variant
  ) ASC

Query time 0.04124

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "127753.20"
    },
    "ordering_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "65095.20"
      },
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_product_features",
            "access_type": "ALL",
            "possible_keys": [
              "PRIMARY",
              "status"
            ],
            "rows_examined_per_scan": 9063,
            "rows_produced_per_join": 904,
            "filtered": "9.98",
            "cost_info": {
              "read_cost": "855.74",
              "eval_cost": "90.41",
              "prefix_cost": "946.15",
              "data_read_per_join": "388K"
            },
            "used_columns": [
              "feature_id",
              "feature_type",
              "status"
            ],
            "attached_condition": "((`s2cart`.`cscart_product_features`.`feature_type` = 'E') and (`s2cart`.`cscart_product_features`.`status` = 'A'))"
          }
        },
        {
          "table": {
            "table_name": "cscart_product_feature_variants",
            "access_type": "ref",
            "possible_keys": [
              "feature_id"
            ],
            "key": "feature_id",
            "used_key_parts": [
              "feature_id"
            ],
            "key_length": "3",
            "ref": [
              "s2cart.cscart_product_features.feature_id"
            ],
            "rows_examined_per_scan": 72,
            "rows_produced_per_join": 65095,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "16273.80",
              "eval_cost": "6509.52",
              "prefix_cost": "23729.47",
              "data_read_per_join": "72M"
            },
            "used_columns": [
              "variant_id",
              "feature_id"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_product_feature_variant_descriptions",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "variant_id",
              "lang_code"
            ],
            "key_length": "9",
            "ref": [
              "s2cart.cscart_product_feature_variants.variant_id",
              "const"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 65095,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "32419.01",
              "eval_cost": "6509.52",
              "prefix_cost": "62658.00",
              "data_read_per_join": "382M"
            },
            "used_columns": [
              "variant_id",
              "variant",
              "lang_code"
            ]
          }
        }
      ]
    }
  }
}