A friend gave me a Retro VIP Key Ring promo code that he redeemed on the VIP rewards page quite some time ago, do these codes expire? has anyone had a similar experience?

I had a very similar experience earlier this year with a 2020 promo code, the promo codes themselves don't expire, in fact I'm pretty sure it will still let you add the code to the shopping cart, but you won't receive the rewards as even if the code doesn't expire the stock of the promotional product in your case the key ring does, as normally the number of units is quite limited.

Ok I understand then I can try to use it in case it is still in stock?

As I said with promo codes for rewards attached to physical products the stock is very determinant, anyway, you can give it a try, you have nothing to lose, let us know how it goes :)

I have already placed the order, you were right I let me add the promotional code, let's see if I'm lucky. By the way, if finally nothing arrives there is nothing I can do?

Yes of course, LEGO support is really good, that happened to me (adding a promo code and not receiving anything with the order), I contacted LEGO support explaining the problem, they answered me very quickly and added 500 VIP points to my account (that's what they usually do in these cases, although logically it can vary depending on which promo code you have used), in my case in fact it was even more points than it cost me to acquire the promo code so it was a pretty good deal.