SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57de2eab42fb46acc943ab62f042900ca58dd0d8fd77a81313c866432d6958a0' 
  AND token = 'qhr3CIHs8KPK6yxeVUJZpbEjBSJrVyn5fDMjLzg/oHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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