Most casinos do not take additional time to process deposits. That said, the processing time also depends on the payment providers if the latter is involved in the transaction.
Instant deposit options are e-wallets, prepaid cards, mobile wallets (not always – depends on the payment provider involved in the transaction), credit/debit cards, and cryptocurrencies (transactions take up to 15 minutes). The slowest deposits options are wire bank transfers, up to several business days.