SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '384a4c27bdefbc222c381fe112705de6c4d4c5e4f1d1ba4c2d53654030029aaf' 
  AND token = 'fX3G/5KKDitTHFRlK1SdTfzRTKaL5CxAAtjpIVGwyjs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00066

JSON explain

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