SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f867a737f66328bb84149cc6900bcb09f618b7c7e26000fbd67b7e426d73a56' 
  AND token = 'EhJbp1Z+CwtC2S3KvIyLHFzzao0JHxR20ZpXvT/+hWQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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