SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6dd031e6cfae859aa11860b234ba73516cf02fc660d9a2fe730526eb27628475' 
  AND token = 'hyyK5mhyUBzNvy9PLOXc559Cy9SRhmvteAeIcR9ZDiY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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