SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85daa80091de8e6a5a7a2906803648449dd4f70daad4e52ccc99820e65275a66' 
  AND token = 'Z8S6zyGBGTTzCfmFLwCve1oXbPh1+YhYuZhFqGDx8L0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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