Searching in EasyEDA in the general search box or in the SHIFT+F Library search can be a bit of a challenge if you're used to Google and other search tools. It seems it is not good at looking for search terms that do not start at or near the front of the name. You can use partial term in the search box. For example searching on "KEY\-SMD\_4P" or "SMD\_4P"finds lots of things\. Searching on "LS9.0" or "-P4.50-LS9.0" finds zero! So you have to be creative in the search terms you use. Often you may get a result by using your search term in Google or Bing (other search engines are available) but prefixing it with EasyEDA which will tend to bring stuff on EasyEDA to the top of the list. Alternatively look for the part on the LCSC.com site and use that to identify the symbol and footprint then you can find from the LCSC (Cxxx) part number it in the library. :)