If you just want to notify the sales rep, you could set up a simple trigger campaign to send an alert email to the Lead Owner, for example:
(Trigger) Revenue Cycle Stage is changed (add constraint > new stage = MQL)
(Flow) Wait 24 hrs > Send Alert to Lead Owner IF (add choice > Lead Status = Open)
You can use the same concept to create a Task in SFDC as well.
It might also be worthwhile to set up some dashboards and lead views in your CRM to show MQLs by Status (create a custom field in your CRM and update it via Marketo triggers to mirror their RCM Stage). You could get creative with using custom CRM fields for timestamping their RCM stage change, or use field history tracking to get some real-time expired SLA dashboards going too.