SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4410e0487308f1243f2904cb55012972f02825520adbf33dd68ffb946ad42445' 
  AND token = 'FFcvYDerqB9nVkjclzx62eRxbpjMpdPmK0Vv79Vx77U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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