Invitation Code

$meta_query = array(
	'relation' => 'AND',
	array(
		'key'     => 'invitation_code',
		'value'   => '9343',
		'compare' => '=',
	),
	array(
		'key'     => 'post_mime_type',
		'value'   => 'user',
		'compare' => '=',
	),
);