HIgh cpu utilization (no replies)

I am using mysql community edition 5.7.20. From past two days my cpu utilization is 150 to 200 % but the connected users are three, in which two are users connected from client side and other one is application user . To identify the issue I have enabled the genral_log at global level for 1 hour and executed the plan for random queries, but the query execution for the queries is 0 to 0.06 sec.
Please help me out to fix the issue.