Positioned in the foyer of the Tesco Hemsworth store where he works, the aptly named 26-year-old has watched on, with little communication with the outside world, as shoppers have gone about their daily routines.
Mr Lockey began his challenge two days ago, to raise awareness of autism and the work that national charity Caudwell Children does to support youngsters with the condition and their families.
And at 2pm this afternoon, the former Hemsworth High School pupil walked free.
He said: “We had around 15,000 people coming in and for everyone who came in, whether they smiled and waved, came over and said hello or just walked by, seeing the box had some sort of an impact.
“Some parents with children with autism came up and told me their stories. It’s definitely left its mark on the community.”
Andy Bailey of Caudwell Children was the brainchild behind the ‘Locked in for Autism’ challenge.
He hoped it would bring the disability to people’s attention.
He said: “Many parents of autistic children have told me that the box is a perfect metaphor for the condition.
“Feeling conspicuous, being viewed from every angle with no place to hide, and struggling to communicate with those outside the box are things that many parents relate to.”
Mr Lockey said his time in the 3x2 metre box had “certainly opened his eyes” to the challenges that autistic children face.
He said: “I felt restricted. I wanted to communicate with people who were coming over to talk to me but it was hard to hear. It got very frustrating at times. The metaphor stands strong.”
Mr Lockey entered the glass box at midday on Wednesday.
By the time he walked out to a crowd of supporters this afternoon, its outside was covered in a sea of pink post-it notes, a touching gesture from admiring and empathetic well wishers.
He said: “The support has been absolutely fantastic.
“People have been sticking post-it notes on the glass panels with their messages.
“The support has really got me through it.”
As well as making autism “the talk of the town”, Mr Lockey has also raised more than £3,500 for Caudwell Children.
To donate, visit www.justgiving.com/fundraising/mickylockedin