SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49d8caf5c72aae0aa5c697ee0453d5b11e4b45e4cd246d46598df365fe47c048' 
  AND token = 'hq/DVWv3Nsw3OVAuXA+iFOJzDzXHAaVX5Kokq2MaAc4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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