SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '76fc95b0c5e51835241127a83ec655cd39fab97fd61beb7c2e94a891ca46d48f' 
  AND token = 'bHm4pIh3M/JlQGxHw/NPEYcLoIEDhTKlkigJtDIWTmI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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