SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9a8fcc317277653a4b74d7e314b77151123d949eb605fa96cd952149a66f3b9' 
  AND token = 'kpFcmKpCcgOeXi6DFCYDKbijqWUH9xV/0t3lI4B5tlU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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