SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f537cb3e89ba893e4ab45499089ed9d9131354752e96f1886c2aed0654d6a441' 
  AND token = 's526tovKCa0fxkNZiHJWuLbSQ4MEqcXmPgpGX5z8sLg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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