SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6da9bd7d5d47af1ea23c7e78c14d31f01d9069dc7d9e2a857d3c0c45eb571330' 
  AND token = 'L1r/W97FP05R+4Uy0UzENoJBjs2khUA8j6e1KgG/Gzo=' 
  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