SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d0b306739835994dfe23fa594f83c2c6bde7c0268f8c82c210d4452fb473e72' 
  AND token = 'uMnSl+WKALmdi4eC9eAuY2UAuQjXKECLBSPm2z8wIN0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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