Making sense of card range query EXPLAIN plans

I was listening to a talk about finding a PAN in a haystack and this slide came up with performance numbers in seconds: This topic is close to my heart because it involves FinTech, databases, and performance investigation/tuning. A card number or PAN or Primary Account Number is a series of 12 to 19 digits. Most popular VISA and MasterCard cards use 16 digits but card systems must handle the…