SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8805f8f9094c3fc580586f70bc6bbf18a79dc5c7acf27cd7346a551c577b7d20' 
  AND token = 'y4vt+7D8p1YJUpRh9X+RJZIFCrUbrquVnwCDvh2Mtpo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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