SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc2e6e48d85e80dd2e151931b95ed9f2c86c10200310b1059f9f36d07242602c' 
  AND token = 'DZIUARUmBSb09KWdCA0pLSaJO8IFxjGh4zpNgFmB0iE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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