posts_where

if (!is_singular('videos')) {
    add_filter('posts_where','posts_where',10,2);
}

function posts_where($where,$query) {

    global $wpdb, $wp_query;

    if (!is_admin()) {

        if ($query->query_vars['post_type'] == 'videos') {

            $new_where = "({$wpdb->postmeta}.meta_key = 'videoid' AND {$wpdb->postmeta}.meta_value != '')";

            if (empty($where))
                $where = $new_where;
            else
                $where = "{$where} AND {$new_where}";

        }

    }

    return $where;

}