SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff67d1d59294c7cf121031269fd97f8ece586802f1b94622ab9d69473ce04663' 
  AND token = 'iNLdsHMu+ylTeFtM+FXjJhjHOr7QgOvBjQph82qbW7U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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