SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e793fc215fc73fa6443e682f8ef70baebafd29dc9564976f9757d8410f92c55c' 
  AND token = 'ZlA92PT6wfA5fkxySp/aw0Xqe27ImlYIp2zc6vu79y0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

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