SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '589126ffa90977883c1215bbf21cfceb9976b967f377e7d233b542cfe9be5547' 
  AND token = 'WujFBbCGRbKzh/6MPfHoXInappi9t1awLey0NBictHM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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