SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a48a14f14e23b1a4456979fdb970d4fcea5c64899781ba9702f547286f49448e' 
  AND token = 'QPfeG1oIVRWFqn/bq3MEKRgVwXIpAApVvsrwbR8k5Ys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

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