Check Distribution
Rewards to be distributed are all recorded on the Distribution Website
Most of the KAR rewards for Karura crowdloan event and Build Acala #1 have been distributed (except for the ones that need to be claimed). You can check your balances in the following ways:
If your rewards are marked as To be Claimed, please follow the guide here to claim.

Check on Polkadot Apps

Go to Polkadot Apps - Karura parachain - Accounts, you need to switch to the Karura parachain and go to the Accounts page.
Make sure your account in the Polkadot{js} extension is switched to Allow use on any chain

Check on Karura Subscan Explorer

Go to the Karura Subscan Explorer, and search your address to see details of balances.