SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ef1c93b71f215645581f5cf1340002ec5424b5d3a068080fa59e578e03b64ed' 
  AND token = 's/yjlmG2PjzbgMOdiQLqxl98rN8PeKxDlAIEJ6FzuNU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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