No, the spell Galder's Tower is new in 5th edition
The adventure module Lost Laboratory of Kwalish (published Nov 2018) introduces this new spell and two other references to the wizard Galder - the spell Galder's Speedy Courier and the magical item Galder's Bubble Pipe. All of these, and the character of Galder, were first published/referenced in this 5e module.
There's a bit of a tragic backstory to these, as their inclusion in this module was intended to immortalise the wizard Galder - the player character of a Redditor and D&D fan, /u/SomeHairyGuy AKA Laurence Withey, who was dying of cancer. Sadly, he passed away at about the same time the module was actually published.
This comicbook.com article summarises the situation well. Essentially, SomeHairyGuy's wish to have his wizard immortalised in D&D lore was picked up by the fan community, causing Wizards to take notice and ultimately Mike Mearls got in touch to ask him to design a signature spell as Galder's legacy.
You can also see the thread on Reddit where Laurence posts initial designs of the spells and item:
Hello everyone, it's me. I still have an unanswered email from Mike Mearls about what kind of signature spell Galder can leave in his legacy.
It's been harder than I expected to come up with a spell!
I'll take the time today if I can to edit this post with more, but to begin with, here's a couple ideas I had: [...]
Barring editing for style and clarity, the published Galder's Tower spell is mechanically almost identical to the version designed by Laurence here in October 2018.
Lost Laboratory of Kwalish itself includes a special acknowledgement for Laurence in its acknowledgements section:
We would also like to extend special acknowledgment of a designer for certain spells and magic items appearing within this adventure. To Laurence Withey — we hope this presentation of your material does justice to Galder, and we humbly thank you for allowing us to include it.