SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7642820475138911a21ad1d7e45f513c47df968d25332dfc4a9eb0a2eeb3f58f' 
  AND token = 'm/RhY+xJWNgEQL6TtLODD5gQaHq5wyhNegrce4dKMuw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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