Find the matching key in qparams and parammap and execute the matching parammap value with the qparam value as the argument.

badmaps.clj

(let [qparams {"cat" "meow"}
      parammap {"cat" #(println "feline says" %), "dog" #(println "canine says" %)}
      foundparam (into {} (filter #(contains? parammap (key %)) qparams))]
  ((get parammap (key (first foundparam))) (val (first foundparam))))
;> feline says meow

; Cleaner?
(let [queryparams {:cat "meow", :cheese "nonsense"}
      functionmap {:cat #(println "feline says" %), :dog #(println "canine says" %)}
      selectedkey (first (select-keys functionmap (keys queryparams)))]
   ((val selectedkey) (queryparams (key selectedkey))))