According to
www.airnav.com:
1. Key Largo does not have scheduled airline service.
2. It has one, privately-owned airport, whose identifier is 07FA.
3. There is no U.S. airport with an identifier of "KYL" at present. (Identifiers can change over time, especially if an airport gains or loses scheduled service.)
Here are details of 07FA:
http://www.airnav.com/airport/07FA
Were you perhaps thinking of Key West (EYW), or Marathon (MTH)?