SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d857958dd8e6be3314b8a391d88ba078169d18991f38eb307b153c7f5132836' 
  AND token = 'IQklAmjT0KA+zOxa8SeUsGDPeUc99IhaMOq3LxT0j+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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