SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '237d58874d0282b7874330ea25d749908577ab4e5c93842fccb1c37cc6c04564' 
  AND token = 'REnC0VT82Zv8IB410FL3Ua5b6+POEndBmT5AvjPFNik=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

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