SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9eb7514e76aeb1ab44d6ff23c9624d86d73278a2e400754d722cd039549dedc1' 
  AND token = 'T95M9GDm/S6j0mYpUICHIVrmBssxPefJYWIvwqzi7fE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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