SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce636176b920c911d975cae9f35bf6c65c8476f9b493b84b396dbc4ae2820bf3' 
  AND token = 'cKVgUhRxZiAyz5tgu9pOLIs3czcb82+X+E50rC7P7CQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}