SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'bf51c88d5dff95cb75ac6172517c2d21ccfa8bfc7cf1b783c6cb27972d298b6c' 
  AND token = '/ovBkzYKKXK8YLlU4codqdANxYCe0LPNGZ/zZnyhgcs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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