SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '228115664e92837df59168701c20649398d67fb61e8285a76af3ec4321c7efd8' 
  AND token = 'Cmm7VP79vUiAsPKOpGIBazy/En6dQuaFqrL3/3Liz3Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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