DES (Department of Education and Skills) guidance on using shared electronic devices for schools is:
- electronics – shared electronic devices such as tablets, touch screens and keyboards should be cleaned between use. Consideration could be given to the use of wipeable covers for electronics to facilitate cleaning
https://www.gov.ie/en/publication/your-questions-answered/#sharing-textbooks-pencils-and-so-on-with-other-children
Microsoft have some useful guidance on caring for and cleaning your Surface device:
Using disinfectant products on your Surface 
You can use many common disinfectant products to safely clean most Microsoft Surface devices. Use pre-moistened disinfectant wipes or apply an isopropyl alcohol (IPA) solution that’s 70% or less to a soft, lint-free cloth to clean the device.
We’ve tested the safety of using the following isopropyl alcohol (IPA) solution and disinfectant wipes on different Surface devices. Be sure to follow the recommendations in the next section as there are specific cleaners that are best for certain devices and finishes.
- Isopropyl alcohol (IPA) solution 70% or less
- PDI Sani-Cloth® Plus
- Covidien™ Alcohol Prep pads
- CaviWipes™
- Total Solutions® Disinfectant Wipes
https://support.microsoft.com/en-us/help/4023504/surface-clean-and-care-for-your-surface
Apple too have some very useful information for cleaning their many products such as iPods, iPhones, iPads and Macbooks.
Is it OK to use a disinfectant on my Apple product? 
Using a 70 percent isopropyl alcohol wipe or Clorox Disinfecting Wipes, you may gently wipe the hard, nonporous surfaces of your Apple product, such as the display, keyboard, or other exterior surfaces. Don’t use bleach. Avoid getting moisture in any opening, and don’t submerge your Apple product in any cleaning agents. Don’t use on fabric or leather surfaces.
https://support.apple.com/en-us/HT204172
Keyboard Covers
Keyboard covers are available from a number of suppliers, some are universal such as the SDTEK Keyboard Protector Desktop Skin Silicone Cover Clear Film Universal (£3.99) or the Green Onions Univesral Keyboard Cap (3 Pack £17.99) both available from Amazon, others are available which are designed to fit specific make and models of well known keyboards such as those from Steritype – (£17.50 + VAT) https://www.steritype.com/steritype-keyboard-covers/
Perhaps you are searching for laptop Keyboard covers in 
different sizes Green Onion and SDTEK can supply a variety of covers for Apple Macbook 13″ and 15″, Microsoft Surface Pro, 13.3″ laptop, 15.6″ and 17″ laptops. These are manufactured with thin flexible material which provides a super tactile typing experience and won’t affect the way you can type.
https://sdtek.com/g/keyboard-protectors
https://greenonionssupply.com/universal-keyboard-cap/