SELECT 
  f.*, 
  d.description 
FROM 
  cscart_form_options as f 
  LEFT JOIN cscart_form_descriptions as d ON d.object_id = f.element_id 
  AND d.lang_code = 'en' 
WHERE 
  f.page_id = 30 
  AND f.status = 'A' 
ORDER BY 
  f.position

Query time 0.00152

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "21.60"
    },
    "ordering_operation": {
      "using_filesort": true,
      "nested_loop": [
        {
          "table": {
            "table_name": "f",
            "access_type": "ref",
            "possible_keys": [
              "page_id"
            ],
            "key": "page_id",
            "used_key_parts": [
              "page_id",
              "status"
            ],
            "key_length": "6",
            "ref": [
              "const",
              "const"
            ],
            "rows_examined_per_scan": 9,
            "rows_produced_per_join": 9,
            "filtered": "100.00",
            "index_condition": "((`webmarco`.`f`.`page_id` <=> 30) and (`webmarco`.`f`.`status` <=> 'A'))",
            "cost_info": {
              "read_cost": "9.00",
              "eval_cost": "1.80",
              "prefix_cost": "10.80",
              "data_read_per_join": "6K"
            },
            "used_columns": [
              "element_id",
              "page_id",
              "parent_id",
              "element_type",
              "value",
              "position",
              "required",
              "status"
            ]
          }
        },
        {
          "table": {
            "table_name": "d",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "object_id",
              "lang_code"
            ],
            "key_length": "9",
            "ref": [
              "webmarco.f.element_id",
              "const"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 9,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "9.00",
              "eval_cost": "1.80",
              "prefix_cost": "21.60",
              "data_read_per_join": "216"
            },
            "used_columns": [
              "object_id",
              "description",
              "lang_code"
            ]
          }
        }
      ]
    }
  }
}

Result

element_id page_id parent_id element_type value position required status description
4 30 0 L 0 N A <p>Thank you for contacting us. We'll answer you at first opportunity.</p>
5 30 0 J mp.admin@webmarco.com 0 N A
8 30 0 E 7 0 N A
9 30 0 K 0 N A
19 30 0 H 1 N A Do you want to know more? Let's Get in Touch!
2 30 0 Y 2 Y A Email
1 30 0 I 3 Y A Full name
7 30 0 I N 4 Y A Subject
3 30 0 T 20 Y A Message