SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '250152abe49d6462af49461ff64f3d7de266da5c2633d3f1459579ef5ee97fbb' 
  AND token = 'EwdakmgVRdwbyMvxUVD1h9pc3nxWNjo4Ov1cY/RzkPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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