SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92667036428785d909920f2ee79412334442d82cabe3037d4fa410f151d03e83' 
  AND token = 'v7Vwyu0kJC7DRyKLkv1KI/bsBmWWCw4tUbVqO29KTUU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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