SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44d0dffb24e5f354d0ef3757759877f47d0d693b8c0c649237b121f3020c458d' 
  AND token = 'j6j/UuWYwThbjRQ33Jr0e9HIvVIzVszbSq4TyAoyqxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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