SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a755289c31b4256f37ce6e94d3222f5f962445c3e2500b3f0a8684a906213d1' 
  AND token = 'YmlZrX0htG/FzMwYcZ7iLY+9KIoHvsd94HC0g+ugg1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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