How to display some settings for super admin user only using Settings API

Test the current user’s role with current_user_can( 'administrator' ):

if ( current_user_can( 'administrator' ) )
{
    add_settings_field( /* arguments */ );
    // or
    add_settings_section( /* arguments */ );
}

Make sure to use the same check when you save the options. Otherwise your regular users might delete the values.