SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48df92a6592918c7784c9c75436ab137f909db86869eab5808dfe14329712842' 
  AND token = 'Z4lo0N/Q/ZdEVf1qPEQLY1BBK3QRSjSkedlPjFGR3JY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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