SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e5f4314e2e21dcedae0c72a79df26aea685ee23a543ef650e33e093a528e94a' 
  AND token = 'TX2wzkr59jrxa/5/dKFRb37iiYq6jYhoBxGUHKoEgQY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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