SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9c7be8cea46576af89cb2c7e42916c0a410bdf6128c7b7d7e68eefb33b833d6' 
  AND token = 'IR3xsQFst2FcwHlFdybhbKYOqzctMZyT7vDBlWFVbxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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