SELECT 
  cscart_product_filters.*, 
  cscart_product_features.feature_type 
FROM 
  cscart_product_filters 
  LEFT JOIN cscart_product_features ON cscart_product_features.feature_id = cscart_product_filters.feature_id 
WHERE 
  cscart_product_filters.filter_id IN (312) 
  AND cscart_product_filters.status = 'A'

Query time 0.00094

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "1.00"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_product_filters",
          "access_type": "const",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "filter_id"
          ],
          "key_length": "3",
          "ref": [
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 1,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "0.00",
            "eval_cost": "0.20",
            "prefix_cost": "0.00",
            "data_read_per_join": "80"
          },
          "used_columns": [
            "filter_id",
            "categories_path",
            "company_id",
            "feature_id",
            "position",
            "field_type",
            "status",
            "round_to",
            "display_count",
            "display",
            "ab__sb_descr_position",
            "mlf_parent_id",
            "mlf_parent_variant",
            "mlf_type",
            "mlf_show_title"
          ]
        }
      },
      {
        "table": {
          "table_name": "cscart_product_features",
          "access_type": "const",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "feature_id"
          ],
          "key_length": "3",
          "ref": [
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 1,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "0.00",
            "eval_cost": "0.20",
            "prefix_cost": "0.00",
            "data_read_per_join": "440"
          },
          "used_columns": [
            "feature_id",
            "feature_type"
          ]
        }
      }
    ]
  }
}