SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82012ff17435e9c171c264834491d9990bbdf31b3670f04ac48af4c05143ee67' 
  AND token = 'hY+w7KzujoJg1mRLv++NQury7qnsJ6SAlv/RrXwHlUU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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