SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4018217fa468a1f6732b989b752db8605963eddc0740936b6f19e46434fd3c3c' 
  AND token = 'Zx4LsLgsxaGCuAIC++W3YIHsed1U48rHXn46eouVVoU=' 
  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"
    }
  }
}