SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70763765b783f7f1eaebee62c83c86fa635161d61848347605983fbd8f7720e2' 
  AND token = 'JvCNNdrck654zAI2dprMSMJi4XpgKlb7BjhJlViNz8U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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