Can a nested loop be compressed into a single line comprehension?

I have a dictionary containing arrays of integers inside, I would like to be able to traverse all the arrays inside to get the maximum stored value. I have achieved all this with a double nested for loop as shown in the following code snippet:

my_dict = {
    'Key_1': [1, 42, 35],
    'Key_2': [12, 24],
    'Key_3': [80, 8, 58],
}
max_value=0
for values in my_dict.values():
    for v in values:
        if v > max_value:
            max_value = v
print(f'Max value is: {max_value}')

My doubt is if it could be compressed into a single line as shown in this non-functional code snippet:

max_value = (((v if v > max_value else 0) for v in values) for values in my_dict.values())
print(f'Max value is: {max_value}')

Thank you very much in advance.

Regards.

Yes, you can just do:

max(max(x) for x in my_dict.values())