SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6ce83678a794d273a4c76c1c7d32e8f6ccc73f1e08015c5bb7da5d2c8658fa66' 
  AND token = 'cHBxyLRPwqCKoo9EIS98zst0ktJf/wKrETy1rdLXfLc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}