SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4dc2d724099b4c1fffd802540a9864b727728809ea9a793cd94f1efc5d2ed0a9' 
  AND token = 'sNeYyE94+d+qW2diWKxeGh5dZiGUGMdP1sceTxc3NHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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