Use of Lounges while connecting at MEX
 

Hello everybody. I am going to have a return MAD-MEX-CUN flight later in autumn. The MAD-MEX is a business class flight operated by Iberia (IB6405) while the MEX-CUN is a Interjet economy ticket in the same booking (IB0276 operated by 4O 2314). I was wondering if
1) I could use OW lounges at MEX.
2) is the OW working overnight

Thank you very much.