SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93e3a5904433753940d3de9090bc2ac21503bda6faff2a038d729237c39b9e0d' 
  AND token = 'F/nSdgXBldzn+YQR2N5YbzIIgTnPGtXCUzOEh7SFOec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

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