SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1e83712c67f0c08bb4db51a6ee98ea0bf153377922c3d10b66586296b9ac009' 
  AND token = 'pzTXl9KDJtZgUcqIZKGZ8OTBtV1iY9mGNRCyXyt9hIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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