SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5464c74eb3c9b5f7d8210330401b9d572e4d30695b32af557ca61f05a2f4e28' 
  AND token = 'YWoSFdfh7xEpGnyOHYEHyUcXyybUdFJyV84/z77L/mI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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