SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7efb0fa96aa05394eb3c8dad0aecda087c7cc525dbf8eac3b2569cacaa46dda' 
  AND token = 'T8hu0mVAuIYowJfok9IyI50Kb+ot6pBeUxTcSag0+MU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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