SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7d4f788bdf7ca0f5e98dc71c9fe9f72b41ee101bda103a9f08bdbd4e84c58f7' 
  AND token = '72iu7BZMXjqdWt1/lf0jPu9BJttXnoMO6Ln0vijbtdM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}