<?php
$input = 'key=value,e4354ahj\,=awet3,asdfa\=asdfa=23f23';
$keyValuePairs = preg_split('/(?<!\\\\),/', $input);
foreach ($keyValuePairs as $pair) {
echo "$key => $value\n";
}
PD9waHAKCiRpbnB1dCA9ICdrZXk9dmFsdWUsZTQzNTRhaGpcLD1hd2V0Myxhc2RmYVw9YXNkZmE9MjNmMjMnOwoka2V5VmFsdWVQYWlycyA9IHByZWdfc3BsaXQoJy8oPzwhXFxcXCksLycsICRpbnB1dCk7Cgpmb3JlYWNoICgka2V5VmFsdWVQYWlycyBhcyAkcGFpcikgewogICAgbGlzdCgka2V5LCAkdmFsdWUpID0gcHJlZ19zcGxpdCgnLyg/PCFcXFxcKT0vJywgJHBhaXIpOwogICAgZWNobyAiJGtleSA9PiAkdmFsdWVcbiI7Cn0KCgo=