SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7c6eb3c33098c72c599d7718500e4a31adcc83f513a9bb9d8309d0df0a474ce7' 
  AND token = '0uCz36tgFjIUKDREskLGzupW6EXnCdNMhBD/7Klp76Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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