SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40db7f34b9c1c531bf4003561b73c253f1b8bad89a6f3c4ec9c08c3877b46980' 
  AND token = 'cURK30roelsc7gWDQiRfnyCoYCWiY1U0PhQcvZBdnfk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}