A WP Query for Posts and Pages but only returns 1 posts/pages

I’m trying to create a wp query that goes through posts and pages and only returns one (the most recent, being a post or a page). So far, I have this:

$conteudo_complexo = new WP_Query(array(
   'post_type'        => array('post', 'page'),
   'posts_per_page'   => 1,
   'orderby'          => 'date',
   'order'            => 'DESC',
   'meta_key'         => 'tipo_de_destaque_homepage',
   'meta_value'       => 'topoeditorial'
));

This is returning multiple pages…

What I’m looking for is something like: go through posts and pages and return only one post or page with that meta_value, whichever is the most recent one.

Note: The meta_key and meta_value is for custom fields.