SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00b75b602adf25e6496472467ffdd5b6269d45154f66dbb90e35fb80cdb51079' 
  AND token = 'cxT71+RJQ70cB+RwrRv1FY7fLdRqSVv5DYEC/vy0B2U=' 
  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