SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3cb43c9c2b1a6dd6f659922aef0e62f121b16a32d09455f03d47fbba024fee6' 
  AND token = 'txSRrP0PRGqcXqF2D3F4KzP3a5a36fq3TpaAYKpubZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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