SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f3ebfd8730c5bf8e3881a8d295d0d96d4c2e0527089ed188139102c120cd26a' 
  AND token = '4rimdhm6UfI35e8xkYZsU6gt+6dl3F1KrRHnWOOwg0w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

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