SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d8ffcb43ad5d0d995e287332c7d951290f57793b6c4654569f96bc41cfb8a11' 
  AND token = 'BUZj75a5ziRA6fl3Lch1XVte0UiVhwvYDrCCxg5qStw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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