product_meta

$meta_query = array(
	'relation' => 'AND',
	array(
		'key'     => 'websima_product_inquiries_single_status',
		'value'   => '1',
		'compare' => '=',
	),
	array(
		'key'     => '_stock_status',
		'value'   => 'instock',
		'compare' => '!=',
	),
);