If diazepam has already expired then you shouldn't take it as expired medicine causes adverse effects rather than providing you relief from muscle spasm.
You can try other self care remedies like
Do gentle massage with topical diclofenac sodium ointment and warm compresses with a heating pad.
Take OTC Naproxen.
Start multi-mineral multivitamin supplement.
Take Oral rehydration solution/potassium/magnesium rich supplement.
Elevate and do stretching exercises.
Both Klonopin and Diazepam are benzodiazepenes so they should be taken together only after consult your doctor to prevent any complication.
So i wouldn't recommend this.
If your symptoms are getting worse then you should see your doctor for a clinical exam.
Or visit ER in case you develop severe pain,swelling,skin discoloration on calf.
Hope this helps.