SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bc5369d21df582c5f2f3e4282d2938422024dcf567e2fd16b4f17aa1bb09e61' 
  AND token = 'oAYA2KEVzXDIDQ7ZrZQuytB9HqechluAlnCmXClyjqo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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