wp_schedule_event custom event time

I use the following code to run a task. this doesn’t require adding a cron schedule.

function setup_my_action() { 
  if (!wp_next_scheduled('my_action')) {
     wp_schedule_single_event(time()+3600, 'my_action');
  }
}
function my_action() { 
  // do something
}
add_action('init','setup_my_action');
add_action('my_action', 'my_action');