SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d93e1faeee31f5a889875e16230015eaefdfc268812f903f145e8e583a750e9' 
  AND token = 'TyU+MiEHsC5ULFVf/vHS19DWoXk3YL0lGrnPkq3mNJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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