SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '809083fc00700d09aa5ff3470c5683c590878b28a927dd93900a8b51cc57b42f' 
  AND token = 'HhwkuJEzSOaJ3qTslZKwdr9BwTxiIEJqCrxLXum8mlA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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