I have booked my airline ticket using my credit card (my name) but for some reasons, I don’t have anymore the physical CC. I heard that airlines need the CC used to book the ticket. Will this be an issue?
First if you have lost your credit card, or don't know where it is, you should absolutely definitely report it to the card company and get it cancelled right now.
Airlines often want you to show the credit card the tickets were booked with as identification, but it is not usually necessary. I've never travelled with an airline that didn't accept an alternative form of identification. You will probably be OK as long as you have sufficient ID, such as a passport or drivers license.
Usually not. They may require it if it's on a different name, say, of your wife.
At least you can show the internet banking of your card.
Contrary to DJClayworth's answer, here's a report of an experience a traveller once had with SriLankan Airlines. His credit card was swallowed by an ATM, and while the airline did not require to see the actual card, they insisted on at least verifying the credit card number before letting him check in.
So, depending on the policy of the airline you're flying with, this might be a problem. Therefore, I would suggest sorting this out with the airline's customer service in advance.