%my_hash = (
	key_1 => $value_1,
	key_2 => $value_2,
	key_3 => $value_3,
	key_4 => $value_4,
	key_5 => $value_5
      );

foreach $key (keys %my_hash) {
     if ($x eq 'key_1' || $key eq $x) {
          do a bunch of stuff;
     }
}