SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7eebfd03af0373273ff0c205dd292ee33fcce38519ee895ac57f8cc2dd26c255' 
  AND token = 'F/P6Wiz6EuukDBk8lFM1jgXyKOndYSEvPuSbH49Xpa8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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