SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3436df23016a18bd8811e91f3d5c0133fd484805f1925531b9e8b4b0bea41558' 
  AND token = 'BBWJAzpLUp8UzHXQGLz/7DlmmexEoFLiraodelznQTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}