SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '757e72bd71df40cb120599e18e891468b59544b16a57aa775711c927e12161ca' 
  AND token = 'eL85QflJCZrnj7YU/F4T0IoisLe9CR/mjb/tbxMKA4k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

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