SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '042b0d31d8a70decf05568888b67c473c5fad5951e00c84ed8bbc9a10fd19463' 
  AND token = 'lKVEXGXvmZgzk2y8J5hGkDKu7b5QfEBvZ1/hvM3tSB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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