SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aecb46369cd9d52c0d597acddb20e29087558bd413a9e845ed49c51fb1ffff8e' 
  AND token = 'tla/Ta1ZSS3dl3bVhG6X2ve4zG8zSnwPYrQHZSkTUJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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