SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd24c53035ef7a5c233eb8a0172c1b73adcc3a949f13d53bb56f562139a4ee0b7' 
  AND token = 'QxRsD3yzuYJGs+yE2uwHiCiQVZe7IFNJ24i7p/9dHoY=' 
  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