SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d4959ea16e0a0f17b89deaa2a7d094052af6e1bd1f85ef66014b7b157ffeba6' 
  AND token = 'lZZe1YlDJsBWb5fdcTmEYjBeufAoZQ9F+samdu0h2Fo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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