SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eabc73741a27a99c7fa365ebf3db472a40209f0343fa39c4e2eba0911226f593' 
  AND token = 'Wr8MXADZsM0LbQEVYW0MBhBpSfLa8bNUjgZFKC9QzxE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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