SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e81a353d7875f0d98630bed737034a283f905a5bb865ef0fbf489870d534ac8' 
  AND token = 'as1TFXD6XySpFbwmbiWGmY/xTaGWZTnicGMnZjR0rsY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

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