SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'cafb05ca1960936c6f9a006c267f342ebef0ca49cd8db6d879d2a9b094081dc7' 
  AND token = '8ne4RArPvZ+IKMIWpQarYHqKV2sNjA4lsyq13V4bp2k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}