SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a99cce425e854d5fcd123c0573fc9a5dd0434aea33a714fd3c1d66105e561cff' 
  AND token = 'fl3PlpzfynNugman1GGP6wke8EUhlSm6IatqHtg5u28=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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