[Unit]
Description=Test for Environment
[Service]
ExecStart=/bin/sh -c 'exit $(test "$VAR1" = "word1 word2") && $(test "$VAR2" = word3) && $(test "$VAR3" = \'$word 5 6\')'
Environment="VAR1=word1 word2" VAR2=word3 "VAR3=$word 5 6"