L2

$meta_query = array(
	'relation' => 'OR',
	array(
		'key'     => 'aw_schedule_syndication',
		'value'   => 'No',
		'compare' => '=',
		'type'    => 'CHAR',
	),
	array(
		'key'     => 'aw_schedule_syndication',
		'compare' => 'NOT EXISTS',
	),
	array(
		'relation' => 'AND',
		array(
			'key'     => 'aw_schedule_syndication',
			'value'   => 'Yes',
			'compare' => '=',
			'type'    => 'CHAR',
		),
		array(
			'key'     => 'aw_syndication_date',
			'value'   => 'strtotime( 'now' )',
			'compare' => '<=',
			'type'    => 'DATETIME',
		),
	),
);