SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '854777d2d3978a5370644e5e346ebd4f75e5e179699fbebf9a202d2459aa3196' 
  AND token = 'UanlJFu2jXdSrXcvkcav4/yhZziCChU92MvixJ+55Wo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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