SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d3e4812f8eb1f1c5683d1fe8b9164e4b41a346be1c1d7a183d4dfca237225ea' 
  AND token = 'wrZY9ivGF55jVuuvrjjU2bg+LcwBFr0FVgaY+sVeMOo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

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