Luci lua rpc - auth token expiry time


I am using lua-mod-rpc package. With the below rpc call, able to get the auth token. But it looks like the auth token expires very quickly. (approx. - after 5 min).
I want to increase the time, Where should I change the expiration time.

curl -k -v -H "Accept: application/json" -H "Content-type: application/json" -X POST --data '
  "id": 1,
  "method": "login",
  "params": [ "root", "root" ]


Hi, I could see in file /etc/config/luci, section "config internal 'sauth".
option sessiontime '3600' is configured.
But for me, my rpc session gets timeout after 5 minutes itself.
any suggestions?