SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c915c4ac74d232e261879052c008784f93f13db5f4d1e6722129e6cd10f9619' 
  AND token = 'BHUJHMZIdhkQSVAjOLrRmk/2Xw+CNd+66zrgxdv6bFk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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