SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd28c2a4a3535a89734f05ae6027e4105c83f0a715b29a4a49c7aef2676624cb8' 
  AND token = 'ntILfWOrkGUpFW2mIhh6Syn4XbaCkmrX+BwueEl2cOE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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