SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9919c27189f90d6191e8f6d4c463b040e4b850623fd70b677a005c22053929d9' 
  AND token = 'WHvIk7J7AQHkoB3BMPvSnzZufA/pCJRUyFeAd/jC6I4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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