SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1851a2702e23b9efb9f5aacc93cfbdba084276815a30be2b03467a57c19a6c1' 
  AND token = 'LnA/Pnrfqafm2FNVO7RmfLLH6DnMw+1v50sG9EFJFDk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

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