logging{
        channel query_logging {
                file "/var/log/query.log" versions 3 size 10m;
                severity debug 3;
                print-time yes;
                print-severity yes;
                print-category yes;
        };

        category queries {
                query_logging;
        };
};

To turn on query logging while DNS service is running; you need to to rndc querylog and check the status with rndc status

shell> rndc querylog
shell> rndc status 
version: 9.x.x
number of zones: 1200
debug level: 3
xfers running: 0
xfers deferred: 0
soa queries in progress: 0
query logging is ON
recursive clients: 0/0/1000
tcp clients: 0/100
server is up and running

query logging is ON indicates that DNS query logging is activated.