Laravel - find by custom column or fail

Try it like this:

Page::where('slug', '=', 'about')->firstOrFail();    
// or without the explicit '='
Page::where('slug', 'about')->firstOrFail();

Update: I'm currently using Laravel 6.9.0 and I confirm that @jeff-puckett is right. Where clause works fine. This is how it works on my tinker.

>>> \App\Models\User::findOrFail('123b5545-5adc-4c59-9a27-00d035c1d212');
>>> App\Models\User
     id: "123b5545-5adc-4c59-9a27-00d035c1d212",
     name: "John",
     surname: "Graham",
     email: "[email protected]",
     email_verified_at: "2020-01-03 16:01:53",
     created_at: "2020-01-03 16:01:59",
     updated_at: "2020-01-03 16:01:59",
     deleted_at: null,

>>> \App\Models\User::where('name', 'Buraco')->findOrFail('123b5545-5adc-4c59-9a27-00d035c1d212');
>>> Illuminate/Database/Eloquent/ModelNotFoundException with message 'No query results for model [App/Models/User] 123b5545-5adc-4c59-9a27-00d035c1d212'


>>> \App\Models\User::where('name', 'John')->findOrFail('123b5545-5adc-4c59-9a27-00d035c1d212');
>>> App\Models\User
     id: "123b5545-5adc-4c59-9a27-00d035c1d212",
     name: "John",
     surname: "Graham",
     email: "[email protected]",
     email_verified_at: "2020-01-03 16:01:53",
     created_at: "2020-01-03 16:01:59",
     updated_at: "2020-01-03 16:01:59",
     deleted_at: null,

Outdated:
It took at least two hours to realize that if you chain firstOrFail() method after where() in Laravel 5.6, it basically tries to retrieve the first record of the table and removes where clauses. So call firstOrFail before where.

Model::firstOrFail()->where('something', $value)