SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '37f433df6e58c75816e89a868538392a4f560c10e533c92faec8b9d00cf77b9b' 
  AND token = 'vrPVO+wIRjFukBi7graRFl1eJMmPQ938G4BjXyBK53w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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