Assuming they unlock your phone with a warrant issued by a judge, and do a very thorough search: you could just have a debit card linked to your crypto, you could just bring the card with you and not have your wallet even on your phone.

The best defense is not being a known criminal who might be subject to searches in the first place. Otherwise, no one is going to go through all the legal hassle of forcing you to unlock your phone and search for evidence that a an address on a decentralized ledger says you own digital assets in excess of 10 grand.