SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6aa5eb2386124990c183d98884247cd071fb6dc6e35c95e29494973ce42908b' 
  AND token = '+9rxWWe8SqpU42Jg/hzyCE9Hf4UHCwGW3cET7uhFZ1s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

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