SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69a47445b95a3576500bf9b57826000444dea899cdf0aec6d029e15e0cf6e305' 
  AND token = 'zIFJsaiRIdSJ7mRZ0AVugOLmWpNTauy5b5BjgXCyYDE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}