[
  {
    "id": 1,
    "translations": {
      "ru": {
        "translation": "русский перевод",
        "approved": true
      },
      "en": {
        "translation": "english translation",
        "approved": false
      }
    }
  },
  {
    "id": 2,
    "translations": {
      "ru": {
        "translation": "русский перевод",
        "approved": true
      }
    }
  }
]

SELECT translation FROM table2 LEFT JOIN table1 USING(id) WHERE lang_code = "en" AND approved = true;