SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e43e88f6bf9b9ceeeaa07f59ca4ee58ec0423c822dbc98dc7d128f0987e65452' 
  AND token = 'erGqxbYFKYISMBeQgaeMz7344n4KOLIraWr/vNkrVVw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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