SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9dcf70620c07c2e4f2eb0254b0ab68c9551dbe101b46c3f06929d2b9bab4cc5f' 
  AND token = 'nGqxJ+WTjMGzn0eWiipCSGOFwJGlQBKM3Hg//fPFwTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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