SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e0f92cd596f360dae86e0df97d1f8884eebc8921945436241149df14286864f' 
  AND token = '4qyWjddoBP+iXMZv920G8XTbHr50Ab9XITx4ef+qrtA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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