The Barclays Premier League club held their Annual General Meeting at the Emirates Stadium on Thursday, which offered shareholders the chance to submit written questions to the board.
The issue over the payment to the American tycoon, who completed his takeover at the north London club in April 2011, was first on the agenda, and came following concerns from supporters at a time of rising ticket costs.
Keswick, however, stressed the board had no issues over the decision, and was one it could look to implement again in the future.
"This fee was proposed by myself and Lord Harris (of Peckham) for the wide range of services provided to Arsenal Football Club by Kroenke Sports and Entertainment," he said.
"KSE is one of the most respected and successful sports organisations in the United States, operating in the most sophisticated sports business market in the world.
"They have an extensive and long experience in modern sports management.
"It is of the utmost importance that as a club we use it to our best advantage to ensure we keep progressing.
"There was no competitive tender for these services as they are directly available to us, and a tender process was inappropriate, and therefore unnecessary.
"We are entirely satisfied the fee was appropriate
In terms of any future fees, that would depend on the nature of the services provided."
Keswick also moved to stress the appointment of Kroenke's son Josh as a non-executive director in December 2013 "underlines the long-term commitment to the club from Stan Kroenke and KSE".
Kroenke gave little away in his brief speech
The American - once dubbed 'Silent Stan' for his preference to stay in the background - preferred to focus on the positives.
"We are quite proud of what we have been able to accomplish
What a wonderful day at Wembley, to win the FA Cup was fantastic," he said as he reflected on last season.
"We had numerous opportunities to get involved in other clubs in Europe, we certainly wanted to get involved in Arsenal
It is a wonderful place.
"We were long acquainted with Arsene Wenger's success and proud to be with him.
"We are pleased he has stayed on for a further three years and look forward to continued success."
Following a rousing speech from manager Arsene Wenger, several subjects were addressed at the meeting, which was less heated than in recent seasons following Arsenal's FA Cup success over Hull in May.
Those included whether the club had a succession plan in mind for when Wenger, who turns 65 later this month, eventually decides to step down, with the chairman stressing Arsenal would expect to be "spoilt for choice" over potential new managers when the time came.
The cost of tickets, especially at away matches, and the limited allocation for Wembley were also raised, while chief executive Ivan Gazidis used graphs to try to explain the need for continued development of all revenue streams to keep the club competitive.
The meeting closed with questions from the floor, with shareholder Nigel Payne pressing the board and Wenger over transfer policy.
Payne, a renowned member of the Arsenal Fanshare scheme, was less than impressed by some of the responses.
"Wenger promised he was going to replace Thomas Vermaelen after he was sold to Barcelona, but this has not happened and all I wanted to know was why," he said.
"I cannot believe the chairman and manager refused to answer a football-related question
Keswick asked Wenger if he would like to say anything about it and he said 'no'.
"This is the first time I have heard a chairman say Wenger is the only one at the club who has any say, transfer-wise
"If you are a managing director of a company and identify weakness and do nothing about it you are sacked.
"Every single Arsenal fan knew we needed a defender and defensive midfielder and he (Wenger) did nothing about it."
Source : PA