Is Security Update 2020-002 still available? I downloaded Security Update 2020-002 a couple of days ago using softwareupdate -d -a from a terminal window.  Today I tried to install it but nothing happened.

$ softwareupdate -i -a --verbose
Software Update Tool

Finding available software
$


It does not show up in the softwareupdate history

$ softwareupdate --history | head
Display Name                                       Version    Date
------------                                       -------    ----
Safari                                             13.1       2020-04-05, 10:26:52
Security Update 2020-001                           10.13.6    2020-03-08, 22:14:32
Safari                                             13.0.5     2020-03-08, 22:14:32


Similarly, no pending updates are shown in the App Store:



The Safari update that I downloaded along with this security update did successfully install in the App Store, without appearing to require any download time.

I'm running 10.13.6.

Has Security Update 2020-002 been disabled or cancelled?  I searched but didn't find anything indicating that it has been.  It still appears in the list of available updates, for example.
Direct link: https://updates.cdn-apple.com/2020/macos/061-90747-20200319-5ded2636-188e-428b-90e6-2ed1507f6f46/SecUpd2020-002HighSierra.dmg

in case it doesn't work, it's due to the key in between. Try the next link. 
Download page: https://support.apple.com/downloads/macos