SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8688dc71b8bd72873aeef9d7fd7462e488764667a4db673d9d2896c8bcc61d07' 
  AND token = 'BAqNpZWMWwIeutxLasQhGGeZp4D8lw1/rCqyF7JBnaQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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