SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df91c1e5468d3fee36df4a59e74bfb89692ab9de368e8ecbe88cb92aea3559a7' 
  AND token = 'Dg1kwJv5y5pE1GiwOi1oXSYW/anpc3AqLhGleUewMp4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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