Well, we're going to have to assume that your Keelback's eggs can be incubated in the same fashion as Natrix and Kingsnake's.
First, the eggs must remain in the same "relative" position as laid! If they are glued together such as Kings' eggs which I doubt, leave them stuck.
If the tank they're in can be used as an incubator (move Mom) this would be best. If not (and we're running out of time) transfer the eggs with great caution, NOT TURNING THEM to a tank with sterile, moist substrate. Some people use vermiculite or sterile potting soil or sterile sphagnum moss. The eggs do not have to be buried however, an easily removed, breathable topping such as moss will aid in maintaing humidity. This also allows you to inspect the eggs as you choose to do so. Your ambient temps noted earlier will be fine.
1)escape proof incubator (I have used seedling incubators, rigid plastic with tight lid which incorporate adjustable vents) work great!
2) unlike birds, reptile fetus "settle" in the egg, air bubble rises to top and MAY NOT be turned. Turning tears the fragile tissues, etc.
3) moist, loose substrate is required. The eggs must breathe, exchanging gases. If the eggs look dry, you may fine mist them from time to time with clean, room temp water.
4) dark, warm, undisturbed location for incubator (no bumping or shaking).
5) keep an eye out for MOULD. The incubator will incubate just about anything - the mineral vermiculite helps to reduce this because it does'nt decompose and primarily has no inherent nutrition for "bugs".
6) be patient, hatching may take almost three months.
Michael