It would be nearly impossible to find out by any means other than to accept service and see what the subpeona says.
However, it is certain that the subpoena is not merely for the production of business records -- otherwise it could be served on anyone in the office who works for you.
So, the subpoena must be for your personal attendance at a deposition or trial.
Lawyer
Retired (mostly)
There must be a case # filed with a court somewhere in the State. But you may not be a party, so looking up your name in the records won't help you know what the subpoena is about -- and the subpoena doesn't need to be filed at all, so searching the court files won't help.