Poor you. But other answers are right - an hour is tooooo long. I do understand also that boys are notoriously bad at WANTING to read. Also if your school isn't concerned yet don't worry, they'll let you know if it really becomes a concern to them.
My girl started primary 4 days after her 4th birthday. They taught them phonics (using Jolly Phonics) to start with. Sound and actions for the letters. Alongside this she was a sheet of words, to start with only 4 at a time repeated twice on the sheet. Story books that were just a few simple words, again kinda repeated. We would sit down for only 5 minutes a day and work on it. If she struggled, I sounded out if I could and then told her the word and just got her to repeat it to me. Then eventually she'd want to tell me the word.
Don't forget they will learn that some letters like a an "o" and a "u" make a sound each but together they make an "ow" or "oo" sound. So they'll get used to trying both and seeing what makes a word they know. More words become able to be sounded out than you think. So if his vocabulary is large he'll soon find the word.
My eldest was a memorizer not a "reader" and she found it harder in the reception and year 1. Now of course she's sorted it but gets new long words incorrect as she wasn't really taught to break it now phonicly.
One idea that came to find is to make pair of cards from his keywords and then play that game where they start with them face down and turn the over to try to find the matching one.
I did see in our local book shop "Transformer" books in different levels from reading with you, to Reception age and more for confident readers. Called "I can Read Books". Or just let him pick books he wants from the library this might spark an interest...
I can't find the web address but from a UK government site I have on file this: (if I find it again I'll post it on)
"In Reception year: To recognise all initial consonant and short vowel sounds (a-z, ch, sh, th) in speech and in writing; to identify and write correct initial letters in response to the letter sound, word, object or picture. To recognise and name each letter of the alphabet and to be aware of alphabetical order through rhmes and songs. Discriminate, write and read final sounds in simple words."