This type of meta tags are in disuse and we recommend you not to pay attention to them. In SEO there are hundreds of other relevant factors and signals to take care of and little time to waste.
Links and recommended readings:
The Meta Keywords of a web page are not taken into account by search engines. If you want to find out why they are no longer relevant, you can get to the bottom of this issue by consulting our wiki.
No. We do not recommend it, although you are free to do so. Using them will neither benefit you nor harm you, but it will waste the time that you need for other tasks that do have an impact on SEO.