2 taxonomies

$tax_query = array(
	'relation' => 'AND',
	array(
		'taxonomy'         => 'taxonomy1',
		'terms'            => '99',
		'field'            => 'term_id',
		'include_children' => true,
	),
	array(
		'taxonomy'         => 'taxonomy2',
		'terms'            => '999',
		'field'            => 'term_id',
		'include_children' => false,
	),
);