add_filter( 'woocommerce_lottery_my_tickets_past_endpoint_query_args', 'custom_order_my_tickets_past' );
function custom_order_my_tickets_past ( $args ){
	$args['meta_key'] = '_lottery_dates_to';
	$args['orderby']  = 'meta_value';
	$args['order']    = 'DESC';
	return $args;
}