I sent this to Qualys support currently still waiting on an answer.
How does one find assets with scan data older than 90 days?
I tried the following and do not get the correct results back.
NOT(lastVmScanDate: [now-90d ... now-1s])
NOT(lastFullScan: [now-90d ... now-1s])
NOT(lastCheckedIn: [now-90d ... now-1s])