display an event by tag

I’m using this to display one random event on a template page:

$query = new WP_Query( array(
'post_type' => 'ai1ec_event',
'posts_per_page' => '1',
'orderby' => 'rand'
)
);

This is working fine, but I need to be able to limit what’s displayed to the tag ‘sticky’ I added for a few events. I tried using events_tags-sticky, that doesn’t work. How would I query by event tag?

https://wordpress.org/plugins/all-in-one-event-calendar/