While we have replacement lock and key sets for sale (click here for the item in our store ---> LOCK AND KEY PURCHASE ), replacing your unique key isn't something we can do for you.
A thorough search is your best solution -- you may find the key. In the event you can locate one key, copies are easy and inexpensive to have made.
All models use Honda motorcycle key blanks HD-75 (also known as X-138).
If your battery is locked into position, contact us for further instruction.
Good luck!