SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bc78dbd136f541a929a9732ce9cd0d09c67e87de40b4b6af4ca44ffe35717d7' 
  AND token = '4utMqLQXfXJWmCwXR4VZzjVt2JiPrl8Enui6jYDUxbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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