SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2532a45dba13127c8410d2ba4b80fb3766865a0c217fdef67c93fa0346ab610' 
  AND token = 'GsJpL1xVZTXQdAvbLastDV3dTHG0eprJSoS65xwzvPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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