SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61ac5cb822a2fd679894f8967537d46f7ea8d60e02339b8ab0b859bcf5b7a918' 
  AND token = 'urDxfNdYS910WcS9pKdWl19NMp0mT/+oNkk4ISv6Ncs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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