SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f934b308f44a57145a18746e3c411b81dcbd50b009fe61af66136ada5bc5ffce' 
  AND token = 'fCNFgmpoHpmP8+g1NkBl6DaDfhHHBkXB9KdNLWs0dCQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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