SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd0bdb762a9666edc92472410c3dbc0fe513c3ec751b29652db7970a2b82a2fa' 
  AND token = 'gbafJ/KWWqkhvrx2hQbFhIromWzYkY+I/djkYtRqcnc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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