SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '611a678831bbf7d776d9ef68bc3721bbd3ca8d8658fb7ee411276261ae835160' 
  AND token = 'eI+J/ejR3tdFLm73AAH91+ZA7Wr7BXPP1npJdTiXr+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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