SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f84b51c0470f75bca910168ae0a39318f1b060ee4b5295d5ad137f3f2cd7a71' 
  AND token = 'kCzncPNneYI/H6TvIpFs1lPyfc6dUrYzhpRlUeoWbDs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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