So, I ran a script to get some data. (Thanks sat0shisgh0st for the idea !)
Here are the logs : http://archive.fo/GwztI

For a sample of 134641 prypto security codes (allegedly a different one per card) :
30,646 Prypto cards that are Not Used and Activated. (22,77%)
9,789 cards were Used. (7,27%)
And 94,206 are Not Used and Not Activated. (69,96%)
If you try to input a completely random security number, it will not tell you that the card doesn't exist, it will tell you that it isn't activated and not used.
So there might as well be "non-existant" cards in the last numbers.

I scrapped some data off the http://cryptoscratchcards.com/ website.
Started with Security Code 10000000 and went up. (As they started with 50 prototypes of 1k DOGE, one was auctioned with number 10000007.

The highest security code that has been used and that I found is : 10103984
So it means there are ranges of activated/used prypto cards.

So basically, the 94,206 not used and not activated cards may be non existent.
Luckily we know there were at least 30,646 activated ("funded") and not used !
I will keep the script running, see if we find anything more in the higher numbers.