SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4c47406782a48fdbeb24c551c7b7357ac72662356233fa81d5dfc4f13276bf0' 
  AND token = 'ySwKh4twu0tDAAh/NSQ2ovGYuLTw+KqG2ugnnUv4KNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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