SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60df5e7c23cf937b4aa0433cc90d837ecd979af84032ed5d6c75093681daed61' 
  AND token = 'WKlIY8JhlSQkcfPSRT5tf+SbH2Tcqm2VAupLlmBbdJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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