This command will show all computers in the AD that have a LAPS password set:

Get-ADComputer -Filter {ms-Mcs-AdmPwd -like "*"}

This command does the opposite and you may want to specify an OU:

Get-ADComputer -Filter {ms-Mcs-AdmPwd -notlike "*"} -SearchBase 'OU=Companies,DC=Contoso,DC=local'

Reference:

https://stackoverflow.com/questions/41717539/powershell-filter-computers-with-no-laps-password-set