SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17f5670f8f98432842255153d15bcbddeff3e8089ecb7635e0640a03cb2f1c32' 
  AND token = 'Po9ZBPm1cWdwoingk6CbeOuX3GtD/ACzGE6pUPFY1A0=' 
  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