SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c2fff95b3014d0581214b80a211313aded5d9793a647b3e4ef9467952888982' 
  AND token = 'IP76AkxE3jqAl9BoBxxp0hDKDoviDhQOwKSEKwT/z5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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