SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5933f0640ccda690631d7761438240473125b2c930a7ca21bba5f3fff9ded95a' 
  AND token = '4lh2SLNFBY7K6d7JTGphrKlW1lHg6d1bOY3iY4KMAcA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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