SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa5fddebb85696bc5fac38696382fcddf8a7677fd67cc9bcea6f429b7f239635' 
  AND token = 'ZLjG0FcdJX2DZnYvxRjkobBiKYRsCKfi/rQRDj++tr4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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