97' Ford Taurus G 3.0L V6, 188K Trunk Lock Won't Turn

As you might or might not know this perticular Taurus does not have a trunk release anywhere else(at least that I have found In 8 years). When you stick the key in to try to open the trunk it will not turn we have also tried the spare key in case of ware n' tare on the key but still nothing a friend of ours suggested graphite and WD40. Will that do it or will it take more drastic measures. Thank you for your time.