SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2f14e41c52e28ab0eec4ad5891590cc8f0762817870b0bd71d46c53c49a13034' 
  AND token = 'n7nhRiY0TIWy/oh6tObXAkIcEpv8usoedzvBuuIy+Po=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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