SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a0cbb52f219afb66568ca82ec0ad410bcc8a17412c18228605f16d8fdf62952' 
  AND token = 'duItry1Kfvi8bAQJO7fFX/+YdSu28IrybGhX81HvNjE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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