SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '6f12433d2843b5077dbc4e3a3618110b6e70dca8f6f56046b240568969d99075' 
  AND token = 'c7QYFa+X55cQ/aWYOhLM3l5nzWlVh/ILlfeJqdL2DN0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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