SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1000757a5987ffa2f9a61459ae8fb7756c2ad7a5b48860164a0edbc99a8df38' 
  AND token = 'kTuH9Ddsr6vag0UhApYcQSpzzewwouZTwuCqpV/5Y5M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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