SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '819b3352c4a405a84948d2dd5cc5fd91089c0f9dad70b2f9dab387f382636067' 
  AND token = 'MvUOnxnAhXBnrRK2aJp3tznVuVwQarPHx6gTRT+a1SM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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