SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f92c26a3648c7e718e2d601f138fe056a354519ebec241e61d85790cbf7ff3a' 
  AND token = 'jWQonJBLPG9K9AHqI0ENUglVOXq7ub5dFlxNN2Qch2U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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