why is boolean returning false?

I have a query and it returns boolean false whenever I use var_dump($row) .

$tokenHash = $query->fetchColumn(10);


    if($query->rowCount() === 0 || (hash_equals($tokenHash, $tokenGet) === FALSE)):
        echo 'Token Inválido!';
        header( "refresh:10;url=listBillsReceive.php" );
        exit;
    else:
        $row = $query->fetch(PDO::FETCH_ASSOC);

Why?