SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fdf04e89ddc58e6a6bdf76af836adeda1c0a4169386012567c86b0d6da4b7b1c' 
  AND token = 'XxJvrnCxllJipJClpQXXyXLysOjBbknSCj/NO7l4/Zs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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