Return multiple rows grouped by a column and named by other column value

Not sure if title is formulated correctly, so there is better explanation:

Table: users_data

uid | key    | value
1   | "age"  | "23"
1   | "city" | "London"
1   | "name" | "John"
2   | "age"  | "19"
2   | "city" | "Tokio"
2   | "name" | "Aiko"

Query: Select data of users aged 23.

Result should look like this:

uid | age  | city     | name
1   | "23" | "London" | "John"

Don't even have current code since I have no idea if it is possible to name columns by value of field, sorry.