SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'cde4680dae507f1a5323163cbc8d170fe6f76a5dc47af6e34ac1f1d1038c299c' 
  AND token = 'OprrhaX6/ufXQIEmY3W3y/HVV4s77oT9pHn+eC2VM9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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