SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f776f8cc590addf061186c9c70c32ab289dc77a1a4edae022a3c98ba0257d022' 
  AND token = 'MuN1ZrpJkSVtejtpXpMnNd9qWmGqiH3QxM8fkQMIN+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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