Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'c12f8f074bf3a4a066e95ac282906ff0dcc3dcdfd6825b930fc3fbaad5afaf9b' 
  AND token = 'XmswHkoOmsr7MxK5DR9lZ6jIGHANFQlQhoKkCBlcPlg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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