SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be9d6ac7a8b2c0f85b0c8b70d63692f535a6eab9226822e540ed9bf9c22bf649' 
  AND token = 'iFWClOphRNNEMe4wHnuoR/tK67Zk4HnlFAkQE5V3F/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}