I'm assuming your substitution fails because the two columns in your input file are tab-delimited, not space-delimited.
Instead of a space in your regular expression, you may use a literal tab character (typed on the command line using Ctrl+V Tab), or you may use an expression that represents a tab, such as [[:blank:]] (matches a single tab or space character).
sed -e 's|^1344P1052_ssl02[[:blank:]]/gs:/prod1|sd://prod1-backup|' \
-e 's|^1344P1052_ssl09[[:blank:]]/gs:/prod1|sd://prod1-backup|' \
-i example.txt
or, even shorter,
sed -e 's|^1344P1052_ssl0[29][[:blank:]]/gs:/prod1|sd://prod1-backup|' \
-i example.txt
I've replaced the space in your pattern with [[:blank:]]. This allows for a single space-or-tab character at that point in the text. I have also combined the two substitutions into a single sed call to avoid reading the whole file twice. I deleted the g flag on both substitution commands as we don't ever expect to make more than a single substitution per line, and I added a ^ anchor to ensure that the patterns match at the start of each line.