SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9f1ca9e1f7c32f317375f03c93a68020cbcc1f6295f71d1af776d5a1dcfe6a4' 
  AND token = 'm60PvNnNdqA6bYZMG7VHdm6vpvkxLyAiFUXuzKhccno=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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