SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b3e0207544f4fd083b340874c5150f5a696006f481e3f5a41839fae814fdc46' 
  AND token = 'Ha1RyTLjkVDcB9Oqze0aGVdDKePj2PKmz4aR1rrRfHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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