SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e377124ee7cc9e56cc7f7a44494be9944c9bf867c115f5cab0860489f7e366a8' 
  AND token = 'sVXgAnPNgIgiMzfRwAipe2ZEop0KypxwQ8+4yJhWeHM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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