SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb932ee67949938a8343780f00791d7898cbffd45010343247e3115e87a0f1cc' 
  AND token = 'sQiz9mxi6V+ihllitfGU8EWheugeyqe+NjpPDEtnTBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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