SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '46fa5d30b9b27e2c487adeb16d8d56e33cc6979fd98f83be37a79b1ea0f9743b' 
  AND token = 'ikeWzWhcp5en7MWiRA4eCOB4EPiZ2Hpjo+rIMbRJ3+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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