SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '598ed0058adab360c3f7102e2f137acfe35166bdb3f8297da20c4441bfb5e52e' 
  AND token = 'mizd9wPrNx58+TmLH+7SEJfL8XhxsC0DO5P2hGQn0is=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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