SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5f08f5f1ed1f20d79ee88f45138c1379b4d8c2900eaa67348b3d0051da48562' 
  AND token = 'IxoqzliiQ6LWmZD/d+25XqMqYsrUv6jKeIrcjM+QTFA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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