SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69f3c4f19eb124344f7abbb2eb367b08a662088906530e7de8a3b71d08c339e0' 
  AND token = '5uNNEJjK90Bw941xU6nT18BClguUGHqBg3loedAvcAE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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