SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd046658f2485efb3d7c64123485beac8265e4679bf27179732d45835a61fd236' 
  AND token = 'XjnjKZIzCuJUbxVhMSDf2TkjLroYLiSfkJdVN6oKfEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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