Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '390aa8b78dbb010fd330d6fea7f8ee3ee32ecd5b7067438022695d5c34995b81' 
  AND token = 'h7BLyfgLsm4YzTlOUi31PQJi77Ib3Z7gXr5szvsYl74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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