SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a32a9ee7986084eedfac03718245f21d1e08546ba5b7653bf33e743283561509' 
  AND token = 'Bzgy+TCFCvptu3p2F524hIbCycEzARtCZ8E4esQtgrM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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