How to post data when web api when it having header: key and token

I having URL http://demo.masti.com/mast1245/api/ with Headers:key=ABZXY1245 with token abct

and server url like

http://demo.masti.com/mast1245/api/masti/reg with method POST.

jsonData = {"f_name":"abc","l_name":"xyz", "email":"abc@gmail.com"}

How can I post data to server in android