SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd352b11ed5769cd10ef44755a3d358d7a2af3e417cb7fbd3928de92be7391147' 
  AND token = 'xLFjpLPoh2qRCrYA4POSXlYsVTNZ4mBXTmnqYIQz3xg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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