SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46729be14094804271016ce1b19b9ac78b74c586dadce9a575b8d219f0a3281f' 
  AND token = 'thB0euhtZJ9xTcGgBS9GRu+RoFgSCK+jh0SI73N9nAw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE Impossible WHERE noticed after reading const tables