SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9888ba597036fe8c10b9ca38e086fd0ea0a4cbf00ede77d05a6656cd97dd9ad4' 
  AND token = 'DQOOBuRgz8zdcM2qZ1UKjGKwwJItrsAD3mOUl4ebpNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

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