SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b34aef8bd99f9dea74cb3ce181c1a8e8d1b91ed3d7321de171b5cf0188df0786' 
  AND token = 'qpJE9dM9/fOMNafBg4DJgsW1NAgCk1Jrea94v+PUb0o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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