SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f22c81a7c452478bcea1600f9cf6af17fe9095ecf34ab37ba55415cae9bb9a76' 
  AND token = 'rEAKmaiRjGql/Ysy7B8ds5gQpCcw4nbx6jVoIWCrg60=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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