Would something like this work?

[reflection.assembly]::LoadWithPartialName("Microsoft.SqlServer.Smo") | Out-Null

$s = new-object ("Microsoft.SqlServer.Management.Smo.Server") "SERVERNAME"

$d = $s.Databases | ?{$_.Name -eq "Sandbox"}

$t = $d.Tables | ?{$_.Name -eq "Table1"}

$t.Indexes | ?{$_.IsUnique} | Select Name