SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '334e39e8bc7230e7269c6d23a36d265db58e405fc8809d67f8ab8443a93bc9ab' 
  AND token = '5fBPPz7Yy2UGVVgKcwvQNglFnvzX76D5UYF6bGG8dHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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