SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf825a94653878ed327ad368828c3b9b30c13c5058a5885aaf29cf207417c158' 
  AND token = '6BwxrL7/QZVIhLPhsPSxWFdPEUv987F/HIWwskHRpak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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