SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d79303d5a199b5583806a3426daddb99a2916f7292be9602bc6f564872a6fbb' 
  AND token = '3uyxw+4KK0D9ZSpGazBCbZPt+j7q30MAmCr7WJQEBBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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