SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4040dbc2f33e2f0862544c8dfd9585ace4e3d7bd2d1caf5db4000c066978b37a' 
  AND token = 'tG0FKPLQ+VSFUIWcje1q7CD/dwaKil9bu0sJmlUqY7g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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