SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d92ecba91234dc9073df5e9c9454d09ccb2b1c94fa54a41157dfcb0bdd46f39' 
  AND token = 'rowfMgxlYhzQujEDJWh+qpzerq5UPsnNvqYBTscNru0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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