SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '270536a0e08d2496794305a9b85cf9c6dbe1c72ca289c4cad9dfca923860bcd8' 
  AND token = 'zk5mFrKqdLeiX7NeCuaBzkUBbTxE6kNBdBMZ2CWCdVk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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