SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '593521665da9d093a768a621cdf2b89087e7a45378336b4e8d897b6687d2980a' 
  AND token = 'YCYFxtggMgTqt/+YVfy1Xu8kFPDbqlfBwjexdyE4pQ4=' 
  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