How to restrict an admin page, if the user is not superadmin?

To remove from the admin menu, you could use remove_menu_page():

add_action( 'admin_menu', function ( ) {
    if (is_super_admin()) 
      return;
    remove_menu_page();
    // or remove_submenu_page( ...
},99);

If for some reason the page still exists, it’s just missing it’s menu link, you could check the get_current_screen() to see if the page is being viewed, and prevent access:

add_action( 'admin_notices', function ( ) {
    if (is_super_admin()) 
      return;
    $screen = get_current_screen();
    if ($screen->parent_base == 'all-in-one-seo-pack') { // or wtv
        wp_die('get out');
    }
},99);