SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '3d783d1372ffb15cce8df300aa6c65ce8ac8e55a3710045434e48ad13c2db141' 
  AND token = 'BsgBtL+FozYCt8Ueah9rUzHtpczI0qU2+gxmPrVY0GE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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