SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10cef697667cbc0a83c3ba2da75bd22ccdba284eb11fe31a005a17fb6e242098' 
  AND token = 'TsR7bLaYuRHlK12iLbeLpuf3An8TbldK4LCfyO/bNS4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

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