This is overkill but reminds me of
https://en.wikipedia.org/wiki/Homomorphic_encryption
...where operations (including search) can be carried out on data that remains encrypted throughout.
Sounds like you only need encryption at rest however. So can you keep tickets in memory for searching perhaps?
Hoping this tool lives up to its own hype:
https://fosdem.org/2026/schedule/event/VEQTLH-infrastructure-as-python/
Performance:
https://docs.pyinfra.com/en/3.x/performance.html