> The false positive rate is calculated as the ratio between the number of negative events wrongly categorized as positive (false positives) and the total number of actual negative events (regardless of classification).

https://en.m.wikipedia.org/wiki/False_positive_rate

54% FPR means half of all people who aren't trying to bring anything illegal onto the plane gets stopped.

Since basically nobody are actually trying to do this, that also means that more than half of all people going through gets stopped.

The ratio of true positives to positives must thus also be vanishingly small.