SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '519266750882e0c9c9286e812a294497b94985a5aae7297d90ca6a64e0d355cc' 
  AND token = 'KYmzbED59BZTDVtR8XyDHU9XqOLoQPhhko2oswXpZG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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