SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08472761758b8dccf56c1097b2076b98085d6f87ee442485ec2d146dcf295fc0' 
  AND token = 'uPzg4g4hTQpW1Ti8wSzQ8rLUrZl7WIXmFBta+v++I78=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}