A quick-and-dirty way to get the current utilization would be to poll these OIDs from OLD-CISCO-INTERFACES-MIB:
* locIfInBitsSec - 1.3.6.1.4.1.9.2.2.1.1.6.x
* locIfInPktsSec - 1.3.6.1.4.1.9.2.2.1.1.7.x
* locIfOutBitsSec - 1.3.6.1.4.1.9.2.2.1.1.8.x
* locIfOutPktsSec - 1.3.6.1.4.1.9.2.2.1.1.9.x
These give you the same numbers as the "input rate" and "output rate" lines from the output of `show interface`. Just replace the "x" with the interface index for Gig2/23 shown in `show snmp mib ifmib ifindex`. The MIB states that it's the "five minute exponentially-decayed moving average", but the actual rate matches whatever you've configured with `load-interval` on the interface (which defaults to 5 minutes).
These OIDs will give you a pretty good point-in-time measurement of the interface's utilization without requiring an external system to keep track of deltas between measurements. However, since it's an exponentially-decayed moving average, it may not be as accurate.