SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9003a01b5578bf2977c428fba8eba750417a11e33b666fc4a981f1de8eae5d13' 
  AND token = 'EaZEvAUwDbFBYZhF5TKVLQAzdK335SeQMCw7e0czfqE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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