SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3d1fca301209ce5367a830d230b23cdd0f87d64dc065b90984b198560ed7d67' 
  AND token = 'Wg99/zjJVg/za+NhTmNwVRAURQLbr36GyAxfsCw+y4o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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