SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd10201562198c27508892e65db2fdc96977a6f87211d24745fec248528f1e843' 
  AND token = 'PNHOu1qxkAJ4gUu0BJYx5fsB+ueHdSLTE4LBITI2vI4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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