SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '001ebf10d36885a22f62f2a5e014bbd53930aea408913ad5d390e959255a87f9' 
  AND token = 'lTQZkWj5v7zk0OLAjprn4OAMd0J5juko3Kki8bmuRlg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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