SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f832d211905a9e36175e97dfbd59976afffd04e9cb8e95561321874ab6c5c45f' 
  AND token = 't7BQwnoPMh4L7F/08LW3GxW1/BvKdujBbM8N4BYiG7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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