Did you look at this page?
https://airport.mastercard.com/en/faq
How does this program differ from Priority Pass or LoungeKey?
In addition to providing access to airport lounges, the Mastercard Airport Experiences provided by LoungeKey program also provides you with dining, spa and retail offers within the airport. Plus, there is no need to carry around an extra card.
How many Complimentary lounge visits do I receive?
Complimentary lounge visits may be provided by your card issuer. Please refer to your Mastercard Airport Experiences provided by LoungeKey online account to view the number of complimentary visits you and/or your guests may have. If you have any additional questions, please contact the Customer Service team by clicking on the Help section of the website or app.
How can I find out if my issuer provides me with complimentary lounge visits?
If your issuer provides complimentary lounge visits, there will be a “Complimentary Visit” section under My Information on the app and under My Account on the web. If you do not have any complimentary visits, this section will not display. If you have additional questions, please the Customer Service team by clicking on the Help section of the website or app.