SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83810c7344d724d0782ed032d6d9f1cdf642d2970ad98f39af803d16239fc0a0' 
  AND token = '8qixNjSYs3SEwCzPjiBQI6vB9vYsswetCvAgXHeVwFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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