$args = array(
	'category_name' => 'Events',
	'meta_query' => array(
		array(
			'key' => 'meta_key_to_order_by',
			'value' => time(),
			'compare' => '>=',
			'type' => 'NUMERIC'
		),
		array(
			'key' => 'some other key',
			'value' => 'key value',
			'compare' => '='
		),
	),
	'meta_key' => 'meta_key_to_order_by',
	'order' => 'ASC',
	'orderby' => 'meta_value'
 );
$events_query = new WP_Query( $args);