SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '69ff46818df2908c0b224ba1a914607c95144c558c1d314d2f576f7cf7d9b087' 
  AND token = '98IWfFevVczGEqWjTwtlJw9/8hYYOdX2SVNHVYTgQg0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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