num_rows() from CI3 on CI4

Hi again,
I have been having problems in verifying if a database record exists by selecting it and returning his row, and then proceed to count the number of rows deciding true(if number of rows bigger than 0) and false(else)

Can you give me a hint, I feel like I'm missing something really simple, and I am typing unnecessary code.
Thank you, the your time.

PHP Code:

public static function verify_user_by_cod($cod)
  {

    $db = db_connect();
    $builder = $db->table('users');

    $builder->select('*');
    $builder->where('cod_user', $cod);
    $query = $builder->get();

    
    if (count($query->getResultArray()) > 0) {
      return true;
    } else {
      return false;
    }
  }