SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a64ac5f21bf42436c503054bee610bb338b13c54f573c98bd979df4ebe3332f9' 
  AND token = 'jj5ZS77HIgGDyNd/nZrEn4GgH/4xyCxAgJFnbLNUMUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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