AirPort Extreme Base Station with simultaneous dual-band support. I'm not close to my AirPort, it's at work, but it is the latest model if that helps.
Ok, I am going to assume that you have an 802.11ac AirPort Extreme base station. That would be model# A1521. Since it's at work, do you have administrator rights to make potential changes or resets to the base station or do your workplace have their own IT department that takes care of these things?
Laptop and tablet are up to date.
That would be the laptop is running Windows 7 with the latest update. What is the make & model of this laptop? Is it yours or does your company own it? ... and how about the Android phone?
They connected fine until about a week ago.
So potentially, either something changed on either device or something changed on the AirPort base station. Do you know if the base station got a firmware update or a configuration change during this timeframe?
Lap gets internet fine when connected to Ethernet.
This would point to either the base station's or the laptop's wireless. This could potentially be an incorrect wireless setting on either.
Both have no issues connecting to any other Wi-Fi networks.
... and this would tend to say that neither device's wireless would be the issue. Which makes me thing that the AirPort base station is where we need to concentrate our troubleshooting. Again, do you have access to this base station and do you know your company's overall network configuration using this base station?