SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43803faa6f7983c078cacac796806ccb2bec2ff6d62364539b0dc77604a796e4' 
  AND token = 'Z9M5k3GHFMXXx39LU80DWnFIXe/bA3grYedOOWN/bPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

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