SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '945c65c3d8f3cd3058df9c4e705fc6c2f1d7f13b571f9d588cd66fe896e65355' 
  AND token = '3hg2DwI6vyVsW+WUePUg94oFJoJx+AyRjb6qTwwLGu0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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