SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '344ed9b14f551de3dcf80b6e06edcd73d6c1c7e9a10250a2a86957d11f647b36' 
  AND token = '8czaDbQEtFO3zFI912WJpALRnlyuncBUoSZTPiTmU9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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