SELECT 
  a.*, 
  b.description 
FROM 
  cscart_currencies as a 
  LEFT JOIN cscart_currency_descriptions as b ON a.currency_code = b.currency_code 
  AND lang_code = 'ru' 
WHERE 
  1 
  AND status IN ('A', 'H') 
ORDER BY 
  a.position

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "read_sorted_file": {
          "filesort": {
            "sort_key": "a.position",
            "table": {
              "table_name": "a",
              "access_type": "ALL",
              "rows": 4,
              "filtered": 100,
              "attached_condition": "a.`status` in ('A','H')"
            }
          }
        }
      },
      {
        "table": {
          "table_name": "b",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "38",
          "used_key_parts": ["currency_code", "lang_code"],
          "ref": ["u2372248_stroyka.a.currency_code", "const"],
          "rows": 1,
          "filtered": 100,
          "attached_condition": "trigcond(b.lang_code = 'ru')"
        }
      }
    ]
  }
}

Result

currency_id currency_code after symbol coefficient is_primary position decimals_separator thousands_separator decimals status description
4 RUB Y 1.00000 Y 0 . , 2 A Рубли