I have not tested this with 10000 users, but I believe it should be OK.
The query is pure SQL and does everything on the DB side, so there will not be too much traffic between the DB and the webserver process.
If unsure, you could keep a backup, then attempt your airdrop. If you have to kill the DB process, then you can always reload the backup. That’s what I’d do to be 100% safe.
I would be very much interested to hear your results.
best regards