SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '859bde2f450e949472006f4a8a3017b2bb458b6c83f9613ca8863152d82f78c5' 
  AND token = 'bBmF3Fg+IqDhkVFinMFaJAcoRrvdo2bdFBpVsdq6AB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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