SELECT 
  * 
FROM 
  ushop_cp_apf_system_field_descriptions 
WHERE 
  lang_code = 'es'

Query time 0.00819

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "0.71"
    },
    "table": {
      "table_name": "ushop_cp_apf_system_field_descriptions",
      "access_type": "ALL",
      "rows_examined_per_scan": 2,
      "rows_produced_per_join": 1,
      "filtered": "50.00",
      "cost_info": {
        "read_cost": "0.61",
        "eval_cost": "0.10",
        "prefix_cost": "0.71",
        "data_read_per_join": "2K"
      },
      "used_columns": [
        "system_field",
        "description",
        "lang_code",
        "cp_valid_alphabet",
        "cp_in_symbols",
        "cp_in_numbers",
        "cp_in_lowercase",
        "cp_in_uppercase",
        "cp_placeholder",
        "cp_prompt",
        "cp_maxlength"
      ],
      "attached_condition": "(`marketplace`.`ushop_cp_apf_system_field_descriptions`.`lang_code` = 'es')"
    }
  }
}