SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9fea04608e95cad515e8c3e89327fddcf82f135c093f1a619db66f507ab417d' 
  AND token = 'xWeC9xsTFBCzkSZVcg3UrfiipFb2wHJCxsucm1WHgHU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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