$wpdb update query in plugin only updating one column

Question

I had to use two separate queries. The $wpdb->update syntax cant deal with calculating based on the existing value. But for the other two fields it works. So like this:

$table = $wpdb->prefix . 'woocommerce_downloadable_product_permissions';

$expiry_date = date("Y-m-d", strtotime("+ 30 days"));
$expiry_time = $expiry_date . ' 00:00:00';

$wpdb->query("UPDATE $table SET 
    download_count = (download_count + 1)
    WHERE order_id = '$post_id'");

$wpdb->update( $table, array( 'downloads_remaining' => '1', 'access_expires' => $expiry_time), array( 'order_id' => $post_id ), array( '%s', '%s' ), array( '%d' ) );