SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7513e198bd5dab4f91c0806bc554ee8d37093589de5ec30ad51935b36603aa8' 
  AND token = '/jiBGsZ06uMgnKEos7OonnrjXr0qTwve08d082WEUmo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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