SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6f76c3f6f150d1ba4d3acb238bd0f11f7f636e7771a274faa008a5fb8974c436' 
  AND token = 'CySoP44VZGHWYI4oLCen1G5SEahUFoWZ8Ya9RNDKVtE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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