SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37ea328c8c65c910a96519beb3861e2d36e31a9c7681738dd877e402d9deeb2e' 
  AND token = 'hvxtLdi7GPbQ4px8ihsatNo8uifltoKv7LAPHtiCV6Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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