SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57c38d3ca69e98a7634c65af2a58c67530babf05d8d1951b96e865eb0297e8e6' 
  AND token = 'e2szu0CURuO0o2hQeqFMkwP8aqCr8ZCleTPrhN+JDOM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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