SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96d81a7a9ce05af67c20af3b74948e6f99e5ab4b63b8b17ad96a4c16dcf25f59' 
  AND token = 'PiqIj5v/hUXRQOGlAYPC4gEy/pzCOgdnB+mR/x7aSUM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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