The more verbose you are, the easier of a time you will have debugging.
The effect on your code readability really depends on how much you're trying to wrap into one line - if you've got a single idea that just takes a lot of different words to express, putting it in one line isn't a big deal in my opinion. But if you're trying to cram multiple ideas into one line you'll lose clarity.
For instance. We'll start with a simple idea that just takes some space to express:
transactionTime = generationTime + retrievalTime + processingTime + loggingTime
And here we have a more complex idea that we happen to express in one line:
logTransactionData(processTransaction(retrieveTransaction(generateTransactionQuery())))
I think that the first example is easier to understand at a glance than the second, even though they're about the same in character length.
So in general: consider how likely it is you'll need to debug the line, as well as your idea-complexity-to-line ratio.