SELECT 
  * 
FROM 
  cscart_menus 
  LEFT JOIN cscart_menus_descriptions ON cscart_menus.menu_id = cscart_menus_descriptions.menu_id 
WHERE 
  cscart_menus_descriptions.lang_code = 'de' 
  AND status = 'A'

Query time 0.00125

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_menus",
      "access_type": "ALL",
      "possible_keys": ["PRIMARY"],
      "rows": 7,
      "filtered": 100,
      "attached_condition": "cscart_menus.`status` = 'A'"
    },
    "table": {
      "table_name": "cscart_menus_descriptions",
      "access_type": "eq_ref",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "9",
      "used_key_parts": ["menu_id", "lang_code"],
      "ref": ["dev.cscart_menus.menu_id", "const"],
      "rows": 1,
      "filtered": 100,
      "index_condition": "cscart_menus_descriptions.lang_code = 'de'"
    }
  }
}