SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8341ba03fec016fe27a1df6408cd9eb3cb43e61689fcae42d6fc4079045739b3' 
  AND token = 'NENcS/VKxI4YS1bLnlgijXM0zbYW+XsjFGrbXx6lfQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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