SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2a63ece99f779c53e48b9cbae617c841e2d1fc753e49313246be3b3dcc272dd6' 
  AND token = 'h/7PNhdMkcok0QC/HpvXrsUsfWDH/d0ydh5KXYKCZyg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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