SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e04a22d22bd7f2c02e01a565f1bfabcb01d85e8b9bf723f0f132d780ee5a2dea' 
  AND token = 'QQqRmJs62KAakF72LPptEjJ8Pdy5bEH/bH/+lIpHeQ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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