I found a solution.
I have to use ['post__in']
$resume_args = array();
$resume_args['post_type'] = 'resume';
$resume_args['posts_per_page'] = -1;
$resume_args['post__in'] = array(9046, 9346); //works!
$resume_args['s'] = 'gassi gehen';
$resumes = new WP_Query($resume_args);