Как переписать код в PDO?

Есть код как его правильно переписать в PDO?

    if (!empty($_POST['email']) && !empty($_POST['apiKey'])) {
        $conn = mysqli_connect("localhost", "root", "", "db_user");
        $email = $POST['email'];
        $apiKey = $_POST['apiKey'];
        $result = array();
        if ($db) {
            $sql = "SELECT * FROM users WHERE email = '".$email."' AND apiKey = '".$apiKey."'";
            $res = mysqli_query($db, $sql);
            if (mysqli_num_rows($res) != 0) {
                $row = mysqli_fetch_assoc($res);
                $result = array("status"=>"success", "message"=>"Data fetched successfully", "login"=> $row['login'], "email"=> $row['email'], "apiKey"=> $row['apiKey']);
            } else $result = array("status"=>"failed", "message"=>"Unauthorised access");
        } else $result = array("status"=>"failed", "message"=>"Database connection failed");
    } else $result = array("status"=>"failed", "message"=>"All fields are required");