SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e652e83c5a0978da33af0c492a20904e6f6352ef115ce3cab161e57ef83bdc5a' 
  AND token = 'xOQa+bsT2jQ+K4L5IGd3/Go2ALHbuRqvl1hAw5b5xkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

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