SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b36e02261a92b7fcddb59b9cb3f1adb9eb99310219ec27e74d539579da3b927' 
  AND token = 'lT1bzkybbNpHOAfimih4+Smb968O1RuJPZx2S0XU1u0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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