Have you wondered, "Why my child doesn't sit more than 5 minutes?" The answer is many young children don't have patience to sit more than 5 minutes. Some children might be calm and able to sit for entire a story-time, but the others just don't, and it is okay.
Young children can sit easily the ration of time as the same as their ages; if a child is 2 years old then he/she can sit calmly 2 minutes. So if you want to read a book for your child who doesn't sit for a long time, pick a book that short and engaging book. Perhaps, if you choose a book that leads to an activity after the reading is better.
For example, 'What Do You See, Shuta?' is a short book that children can engage easily and can lead to after reading activities such as physical activity and art and craft. In this book, Shuta goes to the backyard with your child, and they meet friendly insects like butterfly, bee, ladybug, and more. After the reading, your child might want to go in the backyard and want to find those insects that have appeared in the book. You can even create an art project to make one of those insect with household items or drawing.
You can integrate this book with Math and Science too; you can count those insects' legs or wings, which promote number sense of young children. You can have discussion of those insect habitats, which briefly introduced in the book where Shuta meets with them.
There are many books that are short and engaging. Choose picture books that attracted and engaging for your child and use the book to create the other activities throughout the day in order to promote whole child development: literacy, physical, Math, Science, Art, and Emotion.