SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a47144cf7a35031661d9bfe37a9a9c6663782514c90d17db940788ff5f78cc5' 
  AND token = 'sgN85OmHXUng7jNH1/rMvMliwu1L+bB4FrhyeLmjW8E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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