SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee29722a9a7a537c0751d46fc1d2711b988e365ae57521afe5f706d1be838374' 
  AND token = 'rdYNurgtxbJMwlhqCqG+25FD/XFc2lWUGIOKG4o89go=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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