SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf0a10c91764df286d9a13dbe925f108ae375e36a87c3f89da39f98e69399853' 
  AND token = '8O2iFGWWySqmHIIl9+un8XTsOZpjO0QUk1MjlehNKGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

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