SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d06c8eb1daf9f59c917f8fb31b3b7d23bd741b00bb09705dfbd1d47a429d486' 
  AND token = 'zHeDFSgpupKiHtt0je2ZozzwA6hM4FgTB6Ftc3HUdKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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