SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26db761a12b92cda9f8cf699eaf5fd49d2c4b72d1360d5a3fd719652541077a8' 
  AND token = 'wdpB0PYVbiQHUlssRqqpMPjZtvp+soOZ6Jm54UjTqus=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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