Is there any faucet that can give even 1 satoshi of BTC immediately without waiting til you have some amount, and without faucethub account?
A faucet could not pay out 1 satoshi, because it falls below the dust limit that is used by the majority of nodes on the network. Further, the fees required to send a transaction would total far more than 1 satoshi, so even if it was possible to confirm such a transaction, it would cost more to do so than the amount transferred.
If you had a lightning network node with the appropriate incoming capacity, you could accept a lightning network payment on 1 satoshi. It is worth mentioning that if the channel were closed with just 1 sat on your side, you would not be able to receive an on-chain tx for this amount, due to the dust limits mentioned above.
Note that service recommendations are off-topic here, so I won't comment on the current availability of such a faucet.