SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b5a6591b7501cd85325d6e507ab4cb3be177ff3db0bb2eef6f0e615cb0d76cbb' 
  AND token = '+yypl7sFpzKmi7FA0mGlbLiGTHeJAf5ElC7bvHHiP0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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