SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebd6c3166de225b52b0e42ff787e165a48fe43f659e5925be9477889df1e97c5' 
  AND token = 'UrY+orLWwxxQl4THbtDTSl9Gqqv37SES/e3WyE4Tc88=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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